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3,383
Minimum Runes to Add to Cast Spell
Hard
<p>Alice has just graduated from wizard school, and wishes to cast a magic spell to celebrate. The magic spell contains certain <strong>focus points</strong> where magic needs to be concentrated, and some of these focus points contain <strong>magic crystals</strong> which serve as the spell&#39;s energy source. Focus points can be linked through <strong>directed runes</strong>, which channel magic flow from one focus point to another.</p> <p>You are given a integer <code>n</code> denoting the <em>number</em> of focus points and an array of integers <code>crystals</code> where <code>crystals[i]</code> indicates a focus point which holds a magic crystal. You are also given two integer arrays <code>flowFrom</code> and <code>flowTo</code>, which represent the existing <strong>directed runes</strong>. The <code>i<sup>th</sup></code> rune allows magic to freely flow from focus point <code>flowFrom[i]</code> to focus point <code>flowTo[i]</code>.</p> <p>You need to find the number of directed runes Alice must add to her spell, such that <em>each</em> focus point either:</p> <ul> <li><strong>Contains</strong> a magic crystal.</li> <li><strong>Receives</strong> magic flow <em>from</em> another focus point.</li> </ul> <p>Return the <strong>minimum</strong> number of directed runes that she should add.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 6, crystals = [0], flowFrom = [0,1,2,3], flowTo = [1,2,3,0]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample0.png" style="width: 250px; height: 252px;" /></p> <p>Add two directed runes:</p> <ul> <li>From focus point&nbsp;0 to focus point&nbsp;4.</li> <li>From focus point 0 to focus point 5.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 7, crystals = [3,5], flowFrom = [0,1,2,3,5], flowTo = [1,2,0,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample1.png" style="width: 250px; height: 250px;" /></p> <p>Add a directed rune from focus point 4 to focus point 2.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= crystals.length &lt;= n</code></li> <li><code>0 &lt;= crystals[i] &lt;= n - 1</code></li> <li><code>1 &lt;= flowFrom.length == flowTo.length &lt;= min(2 * 10<sup>5</sup>, (n * (n - 1)) / 2)</code></li> <li><code>0 &lt;= flowFrom[i], flowTo[i] &lt;= n - 1</code></li> <li><code>flowFrom[i] != flowTo[i]</code></li> <li>All pre-existing directed runes are <strong>distinct</strong>.</li> </ul>
Depth-First Search; Breadth-First Search; Union Find; Graph; Topological Sort; Array
Go
func minRunesToAdd(n int, crystals []int, flowFrom []int, flowTo []int) (ans int) { g := make([][]int, n) for i := 0; i < len(flowFrom); i++ { a, b := flowFrom[i], flowTo[i] g[a] = append(g[a], b) } vis := make([]int, n) for _, x := range crystals { vis[x] = 1 } bfs := func(q []int) { for len(q) > 0 { a := q[0] q = q[1:] for _, b := range g[a] { if vis[b] == 1 { continue } vis[b] = 1 q = append(q, b) } } } seq := []int{} var dfs func(a int) dfs = func(a int) { vis[a] = 2 for _, b := range g[a] { if vis[b] > 0 { continue } dfs(b) } seq = append(seq, a) } q := crystals bfs(q) for i := 0; i < n; i++ { if vis[i] == 0 { dfs(i) } } for i, j := 0, len(seq)-1; i < j; i, j = i+1, j-1 { seq[i], seq[j] = seq[j], seq[i] } for _, i := range seq { if vis[i] == 2 { q = []int{i} vis[i] = 1 bfs(q) ans++ } } return }
3,383
Minimum Runes to Add to Cast Spell
Hard
<p>Alice has just graduated from wizard school, and wishes to cast a magic spell to celebrate. The magic spell contains certain <strong>focus points</strong> where magic needs to be concentrated, and some of these focus points contain <strong>magic crystals</strong> which serve as the spell&#39;s energy source. Focus points can be linked through <strong>directed runes</strong>, which channel magic flow from one focus point to another.</p> <p>You are given a integer <code>n</code> denoting the <em>number</em> of focus points and an array of integers <code>crystals</code> where <code>crystals[i]</code> indicates a focus point which holds a magic crystal. You are also given two integer arrays <code>flowFrom</code> and <code>flowTo</code>, which represent the existing <strong>directed runes</strong>. The <code>i<sup>th</sup></code> rune allows magic to freely flow from focus point <code>flowFrom[i]</code> to focus point <code>flowTo[i]</code>.</p> <p>You need to find the number of directed runes Alice must add to her spell, such that <em>each</em> focus point either:</p> <ul> <li><strong>Contains</strong> a magic crystal.</li> <li><strong>Receives</strong> magic flow <em>from</em> another focus point.</li> </ul> <p>Return the <strong>minimum</strong> number of directed runes that she should add.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 6, crystals = [0], flowFrom = [0,1,2,3], flowTo = [1,2,3,0]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample0.png" style="width: 250px; height: 252px;" /></p> <p>Add two directed runes:</p> <ul> <li>From focus point&nbsp;0 to focus point&nbsp;4.</li> <li>From focus point 0 to focus point 5.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 7, crystals = [3,5], flowFrom = [0,1,2,3,5], flowTo = [1,2,0,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample1.png" style="width: 250px; height: 250px;" /></p> <p>Add a directed rune from focus point 4 to focus point 2.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= crystals.length &lt;= n</code></li> <li><code>0 &lt;= crystals[i] &lt;= n - 1</code></li> <li><code>1 &lt;= flowFrom.length == flowTo.length &lt;= min(2 * 10<sup>5</sup>, (n * (n - 1)) / 2)</code></li> <li><code>0 &lt;= flowFrom[i], flowTo[i] &lt;= n - 1</code></li> <li><code>flowFrom[i] != flowTo[i]</code></li> <li>All pre-existing directed runes are <strong>distinct</strong>.</li> </ul>
Depth-First Search; Breadth-First Search; Union Find; Graph; Topological Sort; Array
Java
class Solution { private int[] vis; private List<Integer>[] g; private List<Integer> seq = new ArrayList<>(); public int minRunesToAdd(int n, int[] crystals, int[] flowFrom, int[] flowTo) { g = new List[n]; Arrays.setAll(g, i -> new ArrayList<>()); for (int i = 0; i < flowFrom.length; ++i) { g[flowFrom[i]].add(flowTo[i]); } Deque<Integer> q = new ArrayDeque<>(); vis = new int[n]; for (int i : crystals) { vis[i] = 1; q.offer(i); } bfs(q); for (int i = 0; i < n; ++i) { if (vis[i] == 0) { dfs(i); } } int ans = 0; for (int i = seq.size() - 1; i >= 0; --i) { int a = seq.get(i); if (vis[a] == 2) { vis[a] = 1; q.clear(); q.offer(a); bfs(q); ++ans; } } return ans; } private void bfs(Deque<Integer> q) { while (!q.isEmpty()) { int a = q.poll(); for (int b : g[a]) { if (vis[b] == 1) { continue; } vis[b] = 1; q.offer(b); } } } private void dfs(int a) { vis[a] = 2; for (int b : g[a]) { if (vis[b] > 0) { continue; } dfs(b); } seq.add(a); } }
3,383
Minimum Runes to Add to Cast Spell
Hard
<p>Alice has just graduated from wizard school, and wishes to cast a magic spell to celebrate. The magic spell contains certain <strong>focus points</strong> where magic needs to be concentrated, and some of these focus points contain <strong>magic crystals</strong> which serve as the spell&#39;s energy source. Focus points can be linked through <strong>directed runes</strong>, which channel magic flow from one focus point to another.</p> <p>You are given a integer <code>n</code> denoting the <em>number</em> of focus points and an array of integers <code>crystals</code> where <code>crystals[i]</code> indicates a focus point which holds a magic crystal. You are also given two integer arrays <code>flowFrom</code> and <code>flowTo</code>, which represent the existing <strong>directed runes</strong>. The <code>i<sup>th</sup></code> rune allows magic to freely flow from focus point <code>flowFrom[i]</code> to focus point <code>flowTo[i]</code>.</p> <p>You need to find the number of directed runes Alice must add to her spell, such that <em>each</em> focus point either:</p> <ul> <li><strong>Contains</strong> a magic crystal.</li> <li><strong>Receives</strong> magic flow <em>from</em> another focus point.</li> </ul> <p>Return the <strong>minimum</strong> number of directed runes that she should add.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 6, crystals = [0], flowFrom = [0,1,2,3], flowTo = [1,2,3,0]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample0.png" style="width: 250px; height: 252px;" /></p> <p>Add two directed runes:</p> <ul> <li>From focus point&nbsp;0 to focus point&nbsp;4.</li> <li>From focus point 0 to focus point 5.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 7, crystals = [3,5], flowFrom = [0,1,2,3,5], flowTo = [1,2,0,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample1.png" style="width: 250px; height: 250px;" /></p> <p>Add a directed rune from focus point 4 to focus point 2.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= crystals.length &lt;= n</code></li> <li><code>0 &lt;= crystals[i] &lt;= n - 1</code></li> <li><code>1 &lt;= flowFrom.length == flowTo.length &lt;= min(2 * 10<sup>5</sup>, (n * (n - 1)) / 2)</code></li> <li><code>0 &lt;= flowFrom[i], flowTo[i] &lt;= n - 1</code></li> <li><code>flowFrom[i] != flowTo[i]</code></li> <li>All pre-existing directed runes are <strong>distinct</strong>.</li> </ul>
Depth-First Search; Breadth-First Search; Union Find; Graph; Topological Sort; Array
Python
class Solution: def minRunesToAdd( self, n: int, crystals: List[int], flowFrom: List[int], flowTo: List[int] ) -> int: def bfs(q: Deque[int]): while q: a = q.popleft() for b in g[a]: if vis[b] == 1: continue vis[b] = 1 q.append(b) def dfs(a: int): vis[a] = 2 for b in g[a]: if vis[b] > 0: continue dfs(b) seq.append(a) g = [[] for _ in range(n)] for a, b in zip(flowFrom, flowTo): g[a].append(b) q = deque(crystals) vis = [0] * n for x in crystals: vis[x] = 1 bfs(q) seq = [] for i in range(n): if vis[i] == 0: dfs(i) seq.reverse() ans = 0 for i in seq: if vis[i] == 2: q = deque([i]) vis[i] = 1 bfs(q) ans += 1 return ans
3,383
Minimum Runes to Add to Cast Spell
Hard
<p>Alice has just graduated from wizard school, and wishes to cast a magic spell to celebrate. The magic spell contains certain <strong>focus points</strong> where magic needs to be concentrated, and some of these focus points contain <strong>magic crystals</strong> which serve as the spell&#39;s energy source. Focus points can be linked through <strong>directed runes</strong>, which channel magic flow from one focus point to another.</p> <p>You are given a integer <code>n</code> denoting the <em>number</em> of focus points and an array of integers <code>crystals</code> where <code>crystals[i]</code> indicates a focus point which holds a magic crystal. You are also given two integer arrays <code>flowFrom</code> and <code>flowTo</code>, which represent the existing <strong>directed runes</strong>. The <code>i<sup>th</sup></code> rune allows magic to freely flow from focus point <code>flowFrom[i]</code> to focus point <code>flowTo[i]</code>.</p> <p>You need to find the number of directed runes Alice must add to her spell, such that <em>each</em> focus point either:</p> <ul> <li><strong>Contains</strong> a magic crystal.</li> <li><strong>Receives</strong> magic flow <em>from</em> another focus point.</li> </ul> <p>Return the <strong>minimum</strong> number of directed runes that she should add.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 6, crystals = [0], flowFrom = [0,1,2,3], flowTo = [1,2,3,0]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample0.png" style="width: 250px; height: 252px;" /></p> <p>Add two directed runes:</p> <ul> <li>From focus point&nbsp;0 to focus point&nbsp;4.</li> <li>From focus point 0 to focus point 5.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 7, crystals = [3,5], flowFrom = [0,1,2,3,5], flowTo = [1,2,0,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3383.Minimum%20Runes%20to%20Add%20to%20Cast%20Spell/images/runesexample1.png" style="width: 250px; height: 250px;" /></p> <p>Add a directed rune from focus point 4 to focus point 2.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= crystals.length &lt;= n</code></li> <li><code>0 &lt;= crystals[i] &lt;= n - 1</code></li> <li><code>1 &lt;= flowFrom.length == flowTo.length &lt;= min(2 * 10<sup>5</sup>, (n * (n - 1)) / 2)</code></li> <li><code>0 &lt;= flowFrom[i], flowTo[i] &lt;= n - 1</code></li> <li><code>flowFrom[i] != flowTo[i]</code></li> <li>All pre-existing directed runes are <strong>distinct</strong>.</li> </ul>
Depth-First Search; Breadth-First Search; Union Find; Graph; Topological Sort; Array
TypeScript
function minRunesToAdd( n: number, crystals: number[], flowFrom: number[], flowTo: number[], ): number { const g: number[][] = Array.from({ length: n }, () => []); for (let i = 0; i < flowFrom.length; i++) { const a = flowFrom[i], b = flowTo[i]; g[a].push(b); } const vis: number[] = Array(n).fill(0); for (const x of crystals) { vis[x] = 1; } const bfs = (q: number[]) => { while (q.length > 0) { const a = q.shift()!; for (const b of g[a]) { if (vis[b] === 1) continue; vis[b] = 1; q.push(b); } } }; const seq: number[] = []; const dfs = (a: number) => { vis[a] = 2; for (const b of g[a]) { if (vis[b] > 0) continue; dfs(b); } seq.push(a); }; bfs(crystals); for (let i = 0; i < n; i++) { if (vis[i] === 0) { dfs(i); } } seq.reverse(); let ans = 0; for (const i of seq) { if (vis[i] === 2) { bfs([i]); vis[i] = 1; ans++; } } return ans; }
3,384
Team Dominance by Pass Success
Hard
<p>Table: <code>Teams</code></p> <pre> +-------------+---------+ | Column Name | Type | +-------------+---------+ | player_id | int | | team_name | varchar | +-------------+---------+ player_id is the unique key for this table. Each row contains the unique identifier for player and the name of one of the teams participating in that match. </pre> <p>Table: <code>Passes</code></p> <pre> +-------------+---------+ | Column Name | Type | +-------------+---------+ | pass_from | int | | time_stamp | varchar | | pass_to | int | +-------------+---------+ (pass_from, time_stamp) is the primary key for this table. pass_from is a foreign key to player_id from Teams table. Each row represents a pass made during a match, time_stamp represents the time in minutes (00:00-90:00) when the pass was made, pass_to is the player_id of the player receiving the pass. </pre> <p>Write a solution to calculate the <strong>dominance score</strong> for each team in<strong> both halves of the match</strong>. The rules are as follows:</p> <ul> <li>A match is divided into two halves: <strong>first half</strong> (<code>00:00</code>-<code><font face="monospace">45:00</font></code>&nbsp;minutes) and <strong>second half </strong>(<code>45:01</code>-<code>90:00</code> minutes)</li> <li>The dominance score is calculated based on successful and intercepted passes: <ul> <li>When pass_to is a player from the <strong>same team</strong>: +<code>1</code> point</li> <li>When pass_to is a player from the <strong>opposing team</strong> (interception): <code>-1</code> point</li> </ul> </li> <li>A higher dominance score indicates better passing performance</li> </ul> <p>Return <em>the result table ordered </em><em>by</em>&nbsp;<code>team_name</code> and&nbsp;<code>half_number</code> <em>in <strong>ascending</strong> order</em>.</p> <p>The result format is in the following example.</p> <p>&nbsp;</p> <p><strong class="example">Example:</strong></p> <div class="example-block"> <p><strong>Input:</strong></p> <p>Teams table:</p> <pre class="example-io"> +------------+-----------+ | player_id | team_name | +------------+-----------+ | 1 | Arsenal | | 2 | Arsenal | | 3 | Arsenal | | 4 | Chelsea | | 5 | Chelsea | | 6 | Chelsea | +------------+-----------+ </pre> <p>Passes table:</p> <pre class="example-io"> +-----------+------------+---------+ | pass_from | time_stamp | pass_to | +-----------+------------+---------+ | 1 | 00:15 | 2 | | 2 | 00:45 | 3 | | 3 | 01:15 | 1 | | 4 | 00:30 | 1 | | 2 | 46:00 | 3 | | 3 | 46:15 | 4 | | 1 | 46:45 | 2 | | 5 | 46:30 | 6 | +-----------+------------+---------+ </pre> <p><strong>Output:</strong></p> <pre class="example-io"> +-----------+-------------+-----------+ | team_name | half_number | dominance | +-----------+-------------+-----------+ | Arsenal | 1 | 3 | | Arsenal | 2 | 1 | | Chelsea | 1 | -1 | | Chelsea | 2 | 1 | +-----------+-------------+-----------+ </pre> <p><strong>Explanation:</strong></p> <ul> <li><strong>First Half (00:00-45:00):</strong> <ul> <li>Arsenal&#39;s passes: <ul> <li>1 &rarr; 2 (00:15): Successful pass (+1)</li> <li>2 &rarr; 3 (00:45): Successful pass (+1)</li> <li>3 &rarr; 1 (01:15): Successful pass (+1)</li> </ul> </li> <li>Chelsea&#39;s passes: <ul> <li>4 &rarr; 1 (00:30): Intercepted by Arsenal (-1)</li> </ul> </li> </ul> </li> <li><strong>Second Half (45:01-90:00):</strong> <ul> <li>Arsenal&#39;s passes: <ul> <li>2 &rarr; 3 (46:00): Successful pass (+1)</li> <li>3 &rarr; 4 (46:15): Intercepted by Chelsea (-1)</li> <li>1 &rarr; 2 (46:45): Successful pass (+1)</li> </ul> </li> <li>Chelsea&#39;s passes: <ul> <li>5 &rarr; 6 (46:30): Successful pass (+1)</li> </ul> </li> </ul> </li> <li>The results are ordered by team_name and then half_number</li> </ul> </div>
Database
Python
import pandas as pd def calculate_team_dominance(teams: pd.DataFrame, passes: pd.DataFrame) -> pd.DataFrame: passes_with_teams = passes.merge( teams, left_on="pass_from", right_on="player_id", suffixes=("", "_team_from") ).merge( teams, left_on="pass_to", right_on="player_id", suffixes=("_team_from", "_team_to"), ) passes_with_teams["half_number"] = passes_with_teams["time_stamp"].apply( lambda x: 1 if x <= "45:00" else 2 ) passes_with_teams["dominance"] = passes_with_teams.apply( lambda row: 1 if row["team_name_team_from"] == row["team_name_team_to"] else -1, axis=1, ) result = ( passes_with_teams.groupby(["team_name_team_from", "half_number"])["dominance"] .sum() .reset_index() ) result.columns = ["team_name", "half_number", "dominance"] result = result.sort_values(by=["team_name", "half_number"]) return result
3,384
Team Dominance by Pass Success
Hard
<p>Table: <code>Teams</code></p> <pre> +-------------+---------+ | Column Name | Type | +-------------+---------+ | player_id | int | | team_name | varchar | +-------------+---------+ player_id is the unique key for this table. Each row contains the unique identifier for player and the name of one of the teams participating in that match. </pre> <p>Table: <code>Passes</code></p> <pre> +-------------+---------+ | Column Name | Type | +-------------+---------+ | pass_from | int | | time_stamp | varchar | | pass_to | int | +-------------+---------+ (pass_from, time_stamp) is the primary key for this table. pass_from is a foreign key to player_id from Teams table. Each row represents a pass made during a match, time_stamp represents the time in minutes (00:00-90:00) when the pass was made, pass_to is the player_id of the player receiving the pass. </pre> <p>Write a solution to calculate the <strong>dominance score</strong> for each team in<strong> both halves of the match</strong>. The rules are as follows:</p> <ul> <li>A match is divided into two halves: <strong>first half</strong> (<code>00:00</code>-<code><font face="monospace">45:00</font></code>&nbsp;minutes) and <strong>second half </strong>(<code>45:01</code>-<code>90:00</code> minutes)</li> <li>The dominance score is calculated based on successful and intercepted passes: <ul> <li>When pass_to is a player from the <strong>same team</strong>: +<code>1</code> point</li> <li>When pass_to is a player from the <strong>opposing team</strong> (interception): <code>-1</code> point</li> </ul> </li> <li>A higher dominance score indicates better passing performance</li> </ul> <p>Return <em>the result table ordered </em><em>by</em>&nbsp;<code>team_name</code> and&nbsp;<code>half_number</code> <em>in <strong>ascending</strong> order</em>.</p> <p>The result format is in the following example.</p> <p>&nbsp;</p> <p><strong class="example">Example:</strong></p> <div class="example-block"> <p><strong>Input:</strong></p> <p>Teams table:</p> <pre class="example-io"> +------------+-----------+ | player_id | team_name | +------------+-----------+ | 1 | Arsenal | | 2 | Arsenal | | 3 | Arsenal | | 4 | Chelsea | | 5 | Chelsea | | 6 | Chelsea | +------------+-----------+ </pre> <p>Passes table:</p> <pre class="example-io"> +-----------+------------+---------+ | pass_from | time_stamp | pass_to | +-----------+------------+---------+ | 1 | 00:15 | 2 | | 2 | 00:45 | 3 | | 3 | 01:15 | 1 | | 4 | 00:30 | 1 | | 2 | 46:00 | 3 | | 3 | 46:15 | 4 | | 1 | 46:45 | 2 | | 5 | 46:30 | 6 | +-----------+------------+---------+ </pre> <p><strong>Output:</strong></p> <pre class="example-io"> +-----------+-------------+-----------+ | team_name | half_number | dominance | +-----------+-------------+-----------+ | Arsenal | 1 | 3 | | Arsenal | 2 | 1 | | Chelsea | 1 | -1 | | Chelsea | 2 | 1 | +-----------+-------------+-----------+ </pre> <p><strong>Explanation:</strong></p> <ul> <li><strong>First Half (00:00-45:00):</strong> <ul> <li>Arsenal&#39;s passes: <ul> <li>1 &rarr; 2 (00:15): Successful pass (+1)</li> <li>2 &rarr; 3 (00:45): Successful pass (+1)</li> <li>3 &rarr; 1 (01:15): Successful pass (+1)</li> </ul> </li> <li>Chelsea&#39;s passes: <ul> <li>4 &rarr; 1 (00:30): Intercepted by Arsenal (-1)</li> </ul> </li> </ul> </li> <li><strong>Second Half (45:01-90:00):</strong> <ul> <li>Arsenal&#39;s passes: <ul> <li>2 &rarr; 3 (46:00): Successful pass (+1)</li> <li>3 &rarr; 4 (46:15): Intercepted by Chelsea (-1)</li> <li>1 &rarr; 2 (46:45): Successful pass (+1)</li> </ul> </li> <li>Chelsea&#39;s passes: <ul> <li>5 &rarr; 6 (46:30): Successful pass (+1)</li> </ul> </li> </ul> </li> <li>The results are ordered by team_name and then half_number</li> </ul> </div>
Database
SQL
# Write your MySQL query statement below WITH T AS ( SELECT t1.team_name, IF(time_stamp <= '45:00', 1, 2) half_number, IF(t1.team_name = t2.team_name, 1, -1) dominance FROM Passes p JOIN Teams t1 ON p.pass_from = t1.player_id JOIN Teams t2 ON p.pass_to = t2.player_id ) SELECT team_name, half_number, SUM(dominance) dominance FROM T GROUP BY 1, 2 ORDER BY 1, 2;
3,385
Minimum Time to Break Locks II
Hard
<p>Bob is stuck in a dungeon and must break <code>n</code> locks, each requiring some amount of <strong>energy</strong> to break. The required energy for each lock is stored in an array called <code>strength</code> where <code>strength[i]</code> indicates the energy needed to break the <code>i<sup>th</sup></code> lock.</p> <p>To break a lock, Bob uses a sword with the following characteristics:</p> <ul> <li>The initial energy of the sword is 0.</li> <li>The initial factor <code><font face="monospace">X</font></code> by which the energy of the sword increases is 1.</li> <li>Every minute, the energy of the sword increases by the current factor <code>X</code>.</li> <li>To break the <code>i<sup>th</sup></code> lock, the energy of the sword must reach at least <code>strength[i]</code>.</li> <li>After breaking a lock, the energy of the sword resets to 0, and the factor <code>X</code> increases by 1.</li> </ul> <p>Your task is to determine the <strong>minimum</strong> time in minutes required for Bob to break all <code>n</code> locks and escape the dungeon.</p> <p>Return the <strong>minimum </strong>time required for Bob to break all <code>n</code> locks.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">strength = [3,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <table> <tbody> <tr> <th>Time</th> <th>Energy</th> <th>X</th> <th>Action</th> <th>Updated X</th> </tr> <tr> <td>0</td> <td>0</td> <td>1</td> <td>Nothing</td> <td>1</td> </tr> <tr> <td>1</td> <td>1</td> <td>1</td> <td>Break 3<sup>rd</sup> Lock</td> <td>2</td> </tr> <tr> <td>2</td> <td>2</td> <td>2</td> <td>Nothing</td> <td>2</td> </tr> <tr> <td>3</td> <td>4</td> <td>2</td> <td>Break 2<sup>nd</sup> Lock</td> <td>3</td> </tr> <tr> <td>4</td> <td>3</td> <td>3</td> <td>Break 1<sup>st</sup> Lock</td> <td>3</td> </tr> </tbody> </table> <p>The locks cannot be broken in less than 4 minutes; thus, the answer is 4.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">strength = [2,5,4]</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <table> <tbody> <tr> <th>Time</th> <th>Energy</th> <th>X</th> <th>Action</th> <th>Updated X</th> </tr> <tr> <td>0</td> <td>0</td> <td>1</td> <td>Nothing</td> <td>1</td> </tr> <tr> <td>1</td> <td>1</td> <td>1</td> <td>Nothing</td> <td>1</td> </tr> <tr> <td>2</td> <td>2</td> <td>1</td> <td>Break 1<sup>st</sup> Lock</td> <td>2</td> </tr> <tr> <td>3</td> <td>2</td> <td>2</td> <td>Nothing</td> <td>2</td> </tr> <tr> <td>4</td> <td>4</td> <td>2</td> <td>Break 3<sup>rd</sup> Lock</td> <td>3</td> </tr> <tr> <td>5</td> <td>3</td> <td>3</td> <td>Nothing</td> <td>3</td> </tr> <tr> <td>6</td> <td>6</td> <td>3</td> <td>Break 2<sup>nd</sup> Lock</td> <td>4</td> </tr> </tbody> </table> <p>The locks cannot be broken in less than 6 minutes; thus, the answer is 6.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>n == strength.length</code></li> <li><code>1 &lt;= n &lt;= 80</code></li> <li><code>1 &lt;= strength[i] &lt;= 10<sup>6</sup></code></li> <li><code>n == strength.length</code></li> </ul>
Depth-First Search; Graph; Array
Java
class MCFGraph { static class Edge { int src, dst, cap, flow, cost; Edge(int src, int dst, int cap, int flow, int cost) { this.src = src; this.dst = dst; this.cap = cap; this.flow = flow; this.cost = cost; } } static class _Edge { int dst, cap, cost; _Edge rev; _Edge(int dst, int cap, int cost) { this.dst = dst; this.cap = cap; this.cost = cost; this.rev = null; } } private int n; private List<List<_Edge>> graph; private List<_Edge> edges; public MCFGraph(int n) { this.n = n; this.graph = new ArrayList<>(); this.edges = new ArrayList<>(); for (int i = 0; i < n; i++) { graph.add(new ArrayList<>()); } } public int addEdge(int src, int dst, int cap, int cost) { assert (0 <= src && src < n); assert (0 <= dst && dst < n); assert (0 <= cap); int m = edges.size(); _Edge e = new _Edge(dst, cap, cost); _Edge re = new _Edge(src, 0, -cost); e.rev = re; re.rev = e; graph.get(src).add(e); graph.get(dst).add(re); edges.add(e); return m; } public Edge getEdge(int i) { assert (0 <= i && i < edges.size()); _Edge e = edges.get(i); _Edge re = e.rev; return new Edge(re.dst, e.dst, e.cap + re.cap, re.cap, e.cost); } public List<Edge> edges() { List<Edge> result = new ArrayList<>(); for (int i = 0; i < edges.size(); i++) { result.add(getEdge(i)); } return result; } public int[] flow(int s, int t, Integer flowLimit) { List<int[]> result = slope(s, t, flowLimit); return result.get(result.size() - 1); } public List<int[]> slope(int s, int t, Integer flowLimit) { assert (0 <= s && s < n); assert (0 <= t && t < n); assert (s != t); if (flowLimit == null) { flowLimit = graph.get(s).stream().mapToInt(e -> e.cap).sum(); } int[] dual = new int[n]; Tuple[] prev = new Tuple[n]; List<int[]> result = new ArrayList<>(); result.add(new int[] {0, 0}); while (true) { if (!refineDual(s, t, dual, prev)) { break; } int f = flowLimit; int v = t; while (prev[v] != null) { Tuple tuple = prev[v]; int u = tuple.first; _Edge e = tuple.second; f = Math.min(f, e.cap); v = u; } v = t; while (prev[v] != null) { Tuple tuple = prev[v]; int u = tuple.first; _Edge e = tuple.second; e.cap -= f; e.rev.cap += f; v = u; } int c = -dual[s]; result.add(new int[] { result.get(result.size() - 1)[0] + f, result.get(result.size() - 1)[1] + f * c}); if (c == result.get(result.size() - 2)[1]) { result.remove(result.size() - 2); } } return result; } private boolean refineDual(int s, int t, int[] dual, Tuple[] prev) { PriorityQueue<int[]> pq = new PriorityQueue<>(Comparator.comparingInt(a -> a[0])); pq.add(new int[] {0, s}); boolean[] visited = new boolean[n]; Integer[] dist = new Integer[n]; Arrays.fill(dist, null); dist[s] = 0; while (!pq.isEmpty()) { int[] current = pq.poll(); int distV = current[0]; int v = current[1]; if (visited[v]) continue; visited[v] = true; if (v == t) break; int dualV = dual[v]; for (_Edge e : graph.get(v)) { int w = e.dst; if (visited[w] || e.cap == 0) continue; int reducedCost = e.cost - dual[w] + dualV; int newDist = distV + reducedCost; Integer distW = dist[w]; if (distW == null || newDist < distW) { dist[w] = newDist; prev[w] = new Tuple(v, e); pq.add(new int[] {newDist, w}); } } } if (!visited[t]) return false; int distT = dist[t]; for (int v = 0; v < n; v++) { if (visited[v]) { dual[v] -= distT - dist[v]; } } return true; } static class Tuple { int first; _Edge second; Tuple(int first, _Edge second) { this.first = first; this.second = second; } } } class Solution { public int findMinimumTime(int[] strength) { int n = strength.length; int s = n * 2; int t = s + 1; MCFGraph g = new MCFGraph(t + 1); for (int i = 0; i < n; i++) { g.addEdge(s, i, 1, 0); g.addEdge(i + n, t, 1, 0); for (int j = 0; j < n; j++) { g.addEdge(i, j + n, 1, (strength[i] - 1) / (j + 1) + 1); } } return g.flow(s, t, n)[1]; } }
3,385
Minimum Time to Break Locks II
Hard
<p>Bob is stuck in a dungeon and must break <code>n</code> locks, each requiring some amount of <strong>energy</strong> to break. The required energy for each lock is stored in an array called <code>strength</code> where <code>strength[i]</code> indicates the energy needed to break the <code>i<sup>th</sup></code> lock.</p> <p>To break a lock, Bob uses a sword with the following characteristics:</p> <ul> <li>The initial energy of the sword is 0.</li> <li>The initial factor <code><font face="monospace">X</font></code> by which the energy of the sword increases is 1.</li> <li>Every minute, the energy of the sword increases by the current factor <code>X</code>.</li> <li>To break the <code>i<sup>th</sup></code> lock, the energy of the sword must reach at least <code>strength[i]</code>.</li> <li>After breaking a lock, the energy of the sword resets to 0, and the factor <code>X</code> increases by 1.</li> </ul> <p>Your task is to determine the <strong>minimum</strong> time in minutes required for Bob to break all <code>n</code> locks and escape the dungeon.</p> <p>Return the <strong>minimum </strong>time required for Bob to break all <code>n</code> locks.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">strength = [3,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <table> <tbody> <tr> <th>Time</th> <th>Energy</th> <th>X</th> <th>Action</th> <th>Updated X</th> </tr> <tr> <td>0</td> <td>0</td> <td>1</td> <td>Nothing</td> <td>1</td> </tr> <tr> <td>1</td> <td>1</td> <td>1</td> <td>Break 3<sup>rd</sup> Lock</td> <td>2</td> </tr> <tr> <td>2</td> <td>2</td> <td>2</td> <td>Nothing</td> <td>2</td> </tr> <tr> <td>3</td> <td>4</td> <td>2</td> <td>Break 2<sup>nd</sup> Lock</td> <td>3</td> </tr> <tr> <td>4</td> <td>3</td> <td>3</td> <td>Break 1<sup>st</sup> Lock</td> <td>3</td> </tr> </tbody> </table> <p>The locks cannot be broken in less than 4 minutes; thus, the answer is 4.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">strength = [2,5,4]</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <table> <tbody> <tr> <th>Time</th> <th>Energy</th> <th>X</th> <th>Action</th> <th>Updated X</th> </tr> <tr> <td>0</td> <td>0</td> <td>1</td> <td>Nothing</td> <td>1</td> </tr> <tr> <td>1</td> <td>1</td> <td>1</td> <td>Nothing</td> <td>1</td> </tr> <tr> <td>2</td> <td>2</td> <td>1</td> <td>Break 1<sup>st</sup> Lock</td> <td>2</td> </tr> <tr> <td>3</td> <td>2</td> <td>2</td> <td>Nothing</td> <td>2</td> </tr> <tr> <td>4</td> <td>4</td> <td>2</td> <td>Break 3<sup>rd</sup> Lock</td> <td>3</td> </tr> <tr> <td>5</td> <td>3</td> <td>3</td> <td>Nothing</td> <td>3</td> </tr> <tr> <td>6</td> <td>6</td> <td>3</td> <td>Break 2<sup>nd</sup> Lock</td> <td>4</td> </tr> </tbody> </table> <p>The locks cannot be broken in less than 6 minutes; thus, the answer is 6.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>n == strength.length</code></li> <li><code>1 &lt;= n &lt;= 80</code></li> <li><code>1 &lt;= strength[i] &lt;= 10<sup>6</sup></code></li> <li><code>n == strength.length</code></li> </ul>
Depth-First Search; Graph; Array
Python
class MCFGraph: class Edge(NamedTuple): src: int dst: int cap: int flow: int cost: int class _Edge: def __init__(self, dst: int, cap: int, cost: int) -> None: self.dst = dst self.cap = cap self.cost = cost self.rev: Optional[MCFGraph._Edge] = None def __init__(self, n: int) -> None: self._n = n self._g: List[List[MCFGraph._Edge]] = [[] for _ in range(n)] self._edges: List[MCFGraph._Edge] = [] def add_edge(self, src: int, dst: int, cap: int, cost: int) -> int: assert 0 <= src < self._n assert 0 <= dst < self._n assert 0 <= cap m = len(self._edges) e = MCFGraph._Edge(dst, cap, cost) re = MCFGraph._Edge(src, 0, -cost) e.rev = re re.rev = e self._g[src].append(e) self._g[dst].append(re) self._edges.append(e) return m def get_edge(self, i: int) -> Edge: assert 0 <= i < len(self._edges) e = self._edges[i] re = cast(MCFGraph._Edge, e.rev) return MCFGraph.Edge(re.dst, e.dst, e.cap + re.cap, re.cap, e.cost) def edges(self) -> List[Edge]: return [self.get_edge(i) for i in range(len(self._edges))] def flow(self, s: int, t: int, flow_limit: Optional[int] = None) -> Tuple[int, int]: return self.slope(s, t, flow_limit)[-1] def slope( self, s: int, t: int, flow_limit: Optional[int] = None ) -> List[Tuple[int, int]]: assert 0 <= s < self._n assert 0 <= t < self._n assert s != t if flow_limit is None: flow_limit = cast(int, sum(e.cap for e in self._g[s])) dual = [0] * self._n prev: List[Optional[Tuple[int, MCFGraph._Edge]]] = [None] * self._n def refine_dual() -> bool: pq = [(0, s)] visited = [False] * self._n dist: List[Optional[int]] = [None] * self._n dist[s] = 0 while pq: dist_v, v = heappop(pq) if visited[v]: continue visited[v] = True if v == t: break dual_v = dual[v] for e in self._g[v]: w = e.dst if visited[w] or e.cap == 0: continue reduced_cost = e.cost - dual[w] + dual_v new_dist = dist_v + reduced_cost dist_w = dist[w] if dist_w is None or new_dist < dist_w: dist[w] = new_dist prev[w] = v, e heappush(pq, (new_dist, w)) else: return False dist_t = dist[t] for v in range(self._n): if visited[v]: dual[v] -= cast(int, dist_t) - cast(int, dist[v]) return True flow = 0 cost = 0 prev_cost_per_flow: Optional[int] = None result = [(flow, cost)] while flow < flow_limit: if not refine_dual(): break f = flow_limit - flow v = t while prev[v] is not None: u, e = cast(Tuple[int, MCFGraph._Edge], prev[v]) f = min(f, e.cap) v = u v = t while prev[v] is not None: u, e = cast(Tuple[int, MCFGraph._Edge], prev[v]) e.cap -= f assert e.rev is not None e.rev.cap += f v = u c = -dual[s] flow += f cost += f * c if c == prev_cost_per_flow: result.pop() result.append((flow, cost)) prev_cost_per_flow = c return result class Solution: def findMinimumTime(self, a: List[int]) -> int: n = len(a) s = n * 2 t = s + 1 g = MCFGraph(t + 1) for i in range(n): g.add_edge(s, i, 1, 0) g.add_edge(i + n, t, 1, 0) for j in range(n): g.add_edge(i, j + n, 1, (a[i] - 1) // (j + 1) + 1) return g.flow(s, t, n)[1]
3,386
Button with Longest Push Time
Easy
<p>You are given a 2D array <code>events</code> which represents a sequence of events where a child pushes a series of buttons on a keyboard.</p> <p>Each <code>events[i] = [index<sub>i</sub>, time<sub>i</sub>]</code> indicates that the button at index <code>index<sub>i</sub></code> was pressed at time <code>time<sub>i</sub></code>.</p> <ul> <li>The array is <strong>sorted</strong> in increasing order of <code>time</code>.</li> <li>The time taken to press a button is the difference in time between consecutive button presses. The time for the first button is simply the time at which it was pressed.</li> </ul> <p>Return the <code>index</code> of the button that took the <strong>longest</strong> time to push. If multiple buttons have the same longest time, return the button with the <strong>smallest</strong> <code>index</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[1,2],[2,5],[3,9],[1,15]]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 1 is pressed at time 2.</li> <li>Button with index 2 is pressed at time 5, so it took <code>5 - 2 = 3</code> units of time.</li> <li>Button with index 3 is pressed at time 9, so it took <code>9 - 5 = 4</code> units of time.</li> <li>Button with index 1 is pressed again at time 15, so it took <code>15 - 9 = 6</code> units of time.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[10,5],[1,7]]</span></p> <p><strong>Output:</strong> <span class="example-io">10</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 10 is pressed at time 5.</li> <li>Button with index 1 is pressed at time 7, so it took <code>7 - 5 = 2</code> units of time.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= events.length &lt;= 1000</code></li> <li><code>events[i] == [index<sub>i</sub>, time<sub>i</sub>]</code></li> <li><code>1 &lt;= index<sub>i</sub>, time<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li>The input is generated such that <code>events</code> is sorted in increasing order of <code>time<sub>i</sub></code>.</li> </ul>
Array
C++
class Solution { public: int buttonWithLongestTime(vector<vector<int>>& events) { int ans = events[0][0], t = events[0][1]; for (int k = 1; k < events.size(); ++k) { int i = events[k][0], t2 = events[k][1], t1 = events[k - 1][1]; int d = t2 - t1; if (d > t || (d == t && ans > i)) { ans = i; t = d; } } return ans; } };
3,386
Button with Longest Push Time
Easy
<p>You are given a 2D array <code>events</code> which represents a sequence of events where a child pushes a series of buttons on a keyboard.</p> <p>Each <code>events[i] = [index<sub>i</sub>, time<sub>i</sub>]</code> indicates that the button at index <code>index<sub>i</sub></code> was pressed at time <code>time<sub>i</sub></code>.</p> <ul> <li>The array is <strong>sorted</strong> in increasing order of <code>time</code>.</li> <li>The time taken to press a button is the difference in time between consecutive button presses. The time for the first button is simply the time at which it was pressed.</li> </ul> <p>Return the <code>index</code> of the button that took the <strong>longest</strong> time to push. If multiple buttons have the same longest time, return the button with the <strong>smallest</strong> <code>index</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[1,2],[2,5],[3,9],[1,15]]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 1 is pressed at time 2.</li> <li>Button with index 2 is pressed at time 5, so it took <code>5 - 2 = 3</code> units of time.</li> <li>Button with index 3 is pressed at time 9, so it took <code>9 - 5 = 4</code> units of time.</li> <li>Button with index 1 is pressed again at time 15, so it took <code>15 - 9 = 6</code> units of time.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[10,5],[1,7]]</span></p> <p><strong>Output:</strong> <span class="example-io">10</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 10 is pressed at time 5.</li> <li>Button with index 1 is pressed at time 7, so it took <code>7 - 5 = 2</code> units of time.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= events.length &lt;= 1000</code></li> <li><code>events[i] == [index<sub>i</sub>, time<sub>i</sub>]</code></li> <li><code>1 &lt;= index<sub>i</sub>, time<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li>The input is generated such that <code>events</code> is sorted in increasing order of <code>time<sub>i</sub></code>.</li> </ul>
Array
Go
func buttonWithLongestTime(events [][]int) int { ans, t := events[0][0], events[0][1] for k, e := range events[1:] { i, t2, t1 := e[0], e[1], events[k][1] d := t2 - t1 if d > t || (d == t && i < ans) { ans, t = i, d } } return ans }
3,386
Button with Longest Push Time
Easy
<p>You are given a 2D array <code>events</code> which represents a sequence of events where a child pushes a series of buttons on a keyboard.</p> <p>Each <code>events[i] = [index<sub>i</sub>, time<sub>i</sub>]</code> indicates that the button at index <code>index<sub>i</sub></code> was pressed at time <code>time<sub>i</sub></code>.</p> <ul> <li>The array is <strong>sorted</strong> in increasing order of <code>time</code>.</li> <li>The time taken to press a button is the difference in time between consecutive button presses. The time for the first button is simply the time at which it was pressed.</li> </ul> <p>Return the <code>index</code> of the button that took the <strong>longest</strong> time to push. If multiple buttons have the same longest time, return the button with the <strong>smallest</strong> <code>index</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[1,2],[2,5],[3,9],[1,15]]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 1 is pressed at time 2.</li> <li>Button with index 2 is pressed at time 5, so it took <code>5 - 2 = 3</code> units of time.</li> <li>Button with index 3 is pressed at time 9, so it took <code>9 - 5 = 4</code> units of time.</li> <li>Button with index 1 is pressed again at time 15, so it took <code>15 - 9 = 6</code> units of time.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[10,5],[1,7]]</span></p> <p><strong>Output:</strong> <span class="example-io">10</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 10 is pressed at time 5.</li> <li>Button with index 1 is pressed at time 7, so it took <code>7 - 5 = 2</code> units of time.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= events.length &lt;= 1000</code></li> <li><code>events[i] == [index<sub>i</sub>, time<sub>i</sub>]</code></li> <li><code>1 &lt;= index<sub>i</sub>, time<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li>The input is generated such that <code>events</code> is sorted in increasing order of <code>time<sub>i</sub></code>.</li> </ul>
Array
Java
class Solution { public int buttonWithLongestTime(int[][] events) { int ans = events[0][0], t = events[0][1]; for (int k = 1; k < events.length; ++k) { int i = events[k][0], t2 = events[k][1], t1 = events[k - 1][1]; int d = t2 - t1; if (d > t || (d == t && ans > i)) { ans = i; t = d; } } return ans; } }
3,386
Button with Longest Push Time
Easy
<p>You are given a 2D array <code>events</code> which represents a sequence of events where a child pushes a series of buttons on a keyboard.</p> <p>Each <code>events[i] = [index<sub>i</sub>, time<sub>i</sub>]</code> indicates that the button at index <code>index<sub>i</sub></code> was pressed at time <code>time<sub>i</sub></code>.</p> <ul> <li>The array is <strong>sorted</strong> in increasing order of <code>time</code>.</li> <li>The time taken to press a button is the difference in time between consecutive button presses. The time for the first button is simply the time at which it was pressed.</li> </ul> <p>Return the <code>index</code> of the button that took the <strong>longest</strong> time to push. If multiple buttons have the same longest time, return the button with the <strong>smallest</strong> <code>index</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[1,2],[2,5],[3,9],[1,15]]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 1 is pressed at time 2.</li> <li>Button with index 2 is pressed at time 5, so it took <code>5 - 2 = 3</code> units of time.</li> <li>Button with index 3 is pressed at time 9, so it took <code>9 - 5 = 4</code> units of time.</li> <li>Button with index 1 is pressed again at time 15, so it took <code>15 - 9 = 6</code> units of time.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[10,5],[1,7]]</span></p> <p><strong>Output:</strong> <span class="example-io">10</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 10 is pressed at time 5.</li> <li>Button with index 1 is pressed at time 7, so it took <code>7 - 5 = 2</code> units of time.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= events.length &lt;= 1000</code></li> <li><code>events[i] == [index<sub>i</sub>, time<sub>i</sub>]</code></li> <li><code>1 &lt;= index<sub>i</sub>, time<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li>The input is generated such that <code>events</code> is sorted in increasing order of <code>time<sub>i</sub></code>.</li> </ul>
Array
Python
class Solution: def buttonWithLongestTime(self, events: List[List[int]]) -> int: ans, t = events[0] for (_, t1), (i, t2) in pairwise(events): d = t2 - t1 if d > t or (d == t and i < ans): ans, t = i, d return ans
3,386
Button with Longest Push Time
Easy
<p>You are given a 2D array <code>events</code> which represents a sequence of events where a child pushes a series of buttons on a keyboard.</p> <p>Each <code>events[i] = [index<sub>i</sub>, time<sub>i</sub>]</code> indicates that the button at index <code>index<sub>i</sub></code> was pressed at time <code>time<sub>i</sub></code>.</p> <ul> <li>The array is <strong>sorted</strong> in increasing order of <code>time</code>.</li> <li>The time taken to press a button is the difference in time between consecutive button presses. The time for the first button is simply the time at which it was pressed.</li> </ul> <p>Return the <code>index</code> of the button that took the <strong>longest</strong> time to push. If multiple buttons have the same longest time, return the button with the <strong>smallest</strong> <code>index</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[1,2],[2,5],[3,9],[1,15]]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 1 is pressed at time 2.</li> <li>Button with index 2 is pressed at time 5, so it took <code>5 - 2 = 3</code> units of time.</li> <li>Button with index 3 is pressed at time 9, so it took <code>9 - 5 = 4</code> units of time.</li> <li>Button with index 1 is pressed again at time 15, so it took <code>15 - 9 = 6</code> units of time.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">events = [[10,5],[1,7]]</span></p> <p><strong>Output:</strong> <span class="example-io">10</span></p> <p><strong>Explanation:</strong></p> <ul> <li>Button with index 10 is pressed at time 5.</li> <li>Button with index 1 is pressed at time 7, so it took <code>7 - 5 = 2</code> units of time.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= events.length &lt;= 1000</code></li> <li><code>events[i] == [index<sub>i</sub>, time<sub>i</sub>]</code></li> <li><code>1 &lt;= index<sub>i</sub>, time<sub>i</sub> &lt;= 10<sup>5</sup></code></li> <li>The input is generated such that <code>events</code> is sorted in increasing order of <code>time<sub>i</sub></code>.</li> </ul>
Array
TypeScript
function buttonWithLongestTime(events: number[][]): number { let [ans, t] = events[0]; for (let k = 1; k < events.length; ++k) { const [i, t2] = events[k]; const d = t2 - events[k - 1][1]; if (d > t || (d === t && i < ans)) { ans = i; t = d; } } return ans; }
3,387
Maximize Amount After Two Days of Conversions
Medium
<p>You are given a string <code>initialCurrency</code>, and you start with <code>1.0</code> of <code>initialCurrency</code>.</p> <p>You are also given four arrays with currency pairs (strings) and rates (real numbers):</p> <ul> <li><code>pairs1[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates1[i]</code> on <strong>day 1</strong>.</li> <li><code>pairs2[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates2[i]</code> on <strong>day 2</strong>.</li> <li>Also, each <code>targetCurrency</code> can be converted back to its corresponding <code>startCurrency</code> at a rate of <code>1 / rate</code>.</li> </ul> <p>You can perform <strong>any</strong> number of conversions, <strong>including zero</strong>, using <code>rates1</code> on day 1, <strong>followed</strong> by any number of additional conversions, <strong>including zero</strong>, using <code>rates2</code> on day 2.</p> <p>Return the <strong>maximum</strong> amount of <code>initialCurrency</code> you can have after performing any number of conversions on both days <strong>in order</strong>.</p> <p><strong>Note: </strong>Conversion rates are valid, and there will be no contradictions in the rates for either day. The rates for the days are independent of each other.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;EUR&quot;, pairs1 = [[&quot;EUR&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;JPY&quot;]], rates1 = [2.0,3.0], pairs2 = [[&quot;JPY&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;CHF&quot;],[&quot;CHF&quot;,&quot;EUR&quot;]], rates2 = [4.0,5.0,6.0]</span></p> <p><strong>Output:</strong> <span class="example-io">720.00000</span></p> <p><strong>Explanation:</strong></p> <p>To get the maximum amount of <strong>EUR</strong>, starting with 1.0 <strong>EUR</strong>:</p> <ul> <li>On Day 1: <ul> <li>Convert <strong>EUR </strong>to <strong>USD</strong> to get 2.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>JPY</strong> to get 6.0 <strong>JPY</strong>.</li> </ul> </li> <li>On Day 2: <ul> <li>Convert <strong>JPY</strong> to <strong>USD</strong> to get 24.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>CHF</strong> to get 120.0 <strong>CHF</strong>.</li> <li>Finally, convert <strong>CHF</strong> to <strong>EUR</strong> to get 720.0 <strong>EUR</strong>.</li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;NGN&quot;, pairs1 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates1 = </span>[9.0]<span class="example-io">, pairs2 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates2 = </span>[6.0]</p> <p><strong>Output:</strong> 1.50000</p> <p><strong>Explanation:</strong></p> <p>Converting <strong>NGN</strong> to <strong>EUR</strong> on day 1 and <strong>EUR</strong> to <strong>NGN</strong> using the inverse rate on day 2 gives the maximum amount.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;USD&quot;, pairs1 = [[&quot;USD&quot;,&quot;EUR&quot;]], rates1 = [1.0], pairs2 = [[&quot;EUR&quot;,&quot;JPY&quot;]], rates2 = [10.0]</span></p> <p><strong>Output:</strong> <span class="example-io">1.00000</span></p> <p><strong>Explanation:</strong></p> <p>In this example, there is no need to make any conversions on either day.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= initialCurrency.length &lt;= 3</code></li> <li><code>initialCurrency</code> consists only of uppercase English letters.</li> <li><code>1 &lt;= n == pairs1.length &lt;= 10</code></li> <li><code>1 &lt;= m == pairs2.length &lt;= 10</code></li> <li><code>pairs1[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!-- notionvc: c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4 --></li> <li><code>pairs2[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!--{C}%3C!%2D%2D%20notionvc%3A%20c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4%20%2D%2D%3E--></li> <li><code>1 &lt;= startCurrency<sub>i</sub>.length, targetCurrency<sub>i</sub>.length &lt;= 3</code></li> <li><code>startCurrency<sub>i</sub></code> and <code>targetCurrency<sub>i</sub></code> consist only of uppercase English letters.</li> <li><code>rates1.length == n</code></li> <li><code>rates2.length == m</code></li> <li><code>1.0 &lt;= rates1[i], rates2[i] &lt;= 10.0</code></li> <li>The input is generated such that there are no contradictions or cycles in the conversion graphs for either day.</li> <li>The input is generated such that the output is <strong>at most</strong> <code>5 * 10<sup>10</sup></code>.</li> </ul>
Depth-First Search; Breadth-First Search; Graph; Array; String
C++
class Solution { public: double maxAmount(string initialCurrency, vector<vector<string>>& pairs1, vector<double>& rates1, vector<vector<string>>& pairs2, vector<double>& rates2) { unordered_map<string, double> d1 = build(pairs1, rates1, initialCurrency); unordered_map<string, double> d2 = build(pairs2, rates2, initialCurrency); double ans = 0; for (const auto& [currency, rate] : d2) { if (d1.find(currency) != d1.end()) { ans = max(ans, d1[currency] / rate); } } return ans; } private: unordered_map<string, double> build(vector<vector<string>>& pairs, vector<double>& rates, const string& init) { unordered_map<string, vector<pair<string, double>>> g; unordered_map<string, double> d; for (int i = 0; i < pairs.size(); ++i) { const string& a = pairs[i][0]; const string& b = pairs[i][1]; double r = rates[i]; g[a].push_back({b, r}); g[b].push_back({a, 1 / r}); } auto dfs = [&](this auto&& dfs, const string& a, double v) -> void { if (d.find(a) != d.end()) { return; } d[a] = v; for (const auto& [b, r] : g[a]) { if (d.find(b) == d.end()) { dfs(b, v * r); } } }; dfs(init, 1.0); return d; } };
3,387
Maximize Amount After Two Days of Conversions
Medium
<p>You are given a string <code>initialCurrency</code>, and you start with <code>1.0</code> of <code>initialCurrency</code>.</p> <p>You are also given four arrays with currency pairs (strings) and rates (real numbers):</p> <ul> <li><code>pairs1[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates1[i]</code> on <strong>day 1</strong>.</li> <li><code>pairs2[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates2[i]</code> on <strong>day 2</strong>.</li> <li>Also, each <code>targetCurrency</code> can be converted back to its corresponding <code>startCurrency</code> at a rate of <code>1 / rate</code>.</li> </ul> <p>You can perform <strong>any</strong> number of conversions, <strong>including zero</strong>, using <code>rates1</code> on day 1, <strong>followed</strong> by any number of additional conversions, <strong>including zero</strong>, using <code>rates2</code> on day 2.</p> <p>Return the <strong>maximum</strong> amount of <code>initialCurrency</code> you can have after performing any number of conversions on both days <strong>in order</strong>.</p> <p><strong>Note: </strong>Conversion rates are valid, and there will be no contradictions in the rates for either day. The rates for the days are independent of each other.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;EUR&quot;, pairs1 = [[&quot;EUR&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;JPY&quot;]], rates1 = [2.0,3.0], pairs2 = [[&quot;JPY&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;CHF&quot;],[&quot;CHF&quot;,&quot;EUR&quot;]], rates2 = [4.0,5.0,6.0]</span></p> <p><strong>Output:</strong> <span class="example-io">720.00000</span></p> <p><strong>Explanation:</strong></p> <p>To get the maximum amount of <strong>EUR</strong>, starting with 1.0 <strong>EUR</strong>:</p> <ul> <li>On Day 1: <ul> <li>Convert <strong>EUR </strong>to <strong>USD</strong> to get 2.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>JPY</strong> to get 6.0 <strong>JPY</strong>.</li> </ul> </li> <li>On Day 2: <ul> <li>Convert <strong>JPY</strong> to <strong>USD</strong> to get 24.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>CHF</strong> to get 120.0 <strong>CHF</strong>.</li> <li>Finally, convert <strong>CHF</strong> to <strong>EUR</strong> to get 720.0 <strong>EUR</strong>.</li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;NGN&quot;, pairs1 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates1 = </span>[9.0]<span class="example-io">, pairs2 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates2 = </span>[6.0]</p> <p><strong>Output:</strong> 1.50000</p> <p><strong>Explanation:</strong></p> <p>Converting <strong>NGN</strong> to <strong>EUR</strong> on day 1 and <strong>EUR</strong> to <strong>NGN</strong> using the inverse rate on day 2 gives the maximum amount.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;USD&quot;, pairs1 = [[&quot;USD&quot;,&quot;EUR&quot;]], rates1 = [1.0], pairs2 = [[&quot;EUR&quot;,&quot;JPY&quot;]], rates2 = [10.0]</span></p> <p><strong>Output:</strong> <span class="example-io">1.00000</span></p> <p><strong>Explanation:</strong></p> <p>In this example, there is no need to make any conversions on either day.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= initialCurrency.length &lt;= 3</code></li> <li><code>initialCurrency</code> consists only of uppercase English letters.</li> <li><code>1 &lt;= n == pairs1.length &lt;= 10</code></li> <li><code>1 &lt;= m == pairs2.length &lt;= 10</code></li> <li><code>pairs1[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!-- notionvc: c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4 --></li> <li><code>pairs2[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!--{C}%3C!%2D%2D%20notionvc%3A%20c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4%20%2D%2D%3E--></li> <li><code>1 &lt;= startCurrency<sub>i</sub>.length, targetCurrency<sub>i</sub>.length &lt;= 3</code></li> <li><code>startCurrency<sub>i</sub></code> and <code>targetCurrency<sub>i</sub></code> consist only of uppercase English letters.</li> <li><code>rates1.length == n</code></li> <li><code>rates2.length == m</code></li> <li><code>1.0 &lt;= rates1[i], rates2[i] &lt;= 10.0</code></li> <li>The input is generated such that there are no contradictions or cycles in the conversion graphs for either day.</li> <li>The input is generated such that the output is <strong>at most</strong> <code>5 * 10<sup>10</sup></code>.</li> </ul>
Depth-First Search; Breadth-First Search; Graph; Array; String
Go
type Pair struct { Key string Value float64 } func maxAmount(initialCurrency string, pairs1 [][]string, rates1 []float64, pairs2 [][]string, rates2 []float64) (ans float64) { d1 := build(pairs1, rates1, initialCurrency) d2 := build(pairs2, rates2, initialCurrency) for currency, rate := range d2 { if val, found := d1[currency]; found { ans = max(ans, val/rate) } } return } func build(pairs [][]string, rates []float64, init string) map[string]float64 { g := make(map[string][]Pair) d := make(map[string]float64) for i := 0; i < len(pairs); i++ { a := pairs[i][0] b := pairs[i][1] r := rates[i] g[a] = append(g[a], Pair{Key: b, Value: r}) g[b] = append(g[b], Pair{Key: a, Value: 1.0 / r}) } dfs(g, d, init, 1.0) return d } func dfs(g map[string][]Pair, d map[string]float64, a string, v float64) { if _, found := d[a]; found { return } d[a] = v for _, pair := range g[a] { b := pair.Key r := pair.Value if _, found := d[b]; !found { dfs(g, d, b, v*r) } } }
3,387
Maximize Amount After Two Days of Conversions
Medium
<p>You are given a string <code>initialCurrency</code>, and you start with <code>1.0</code> of <code>initialCurrency</code>.</p> <p>You are also given four arrays with currency pairs (strings) and rates (real numbers):</p> <ul> <li><code>pairs1[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates1[i]</code> on <strong>day 1</strong>.</li> <li><code>pairs2[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates2[i]</code> on <strong>day 2</strong>.</li> <li>Also, each <code>targetCurrency</code> can be converted back to its corresponding <code>startCurrency</code> at a rate of <code>1 / rate</code>.</li> </ul> <p>You can perform <strong>any</strong> number of conversions, <strong>including zero</strong>, using <code>rates1</code> on day 1, <strong>followed</strong> by any number of additional conversions, <strong>including zero</strong>, using <code>rates2</code> on day 2.</p> <p>Return the <strong>maximum</strong> amount of <code>initialCurrency</code> you can have after performing any number of conversions on both days <strong>in order</strong>.</p> <p><strong>Note: </strong>Conversion rates are valid, and there will be no contradictions in the rates for either day. The rates for the days are independent of each other.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;EUR&quot;, pairs1 = [[&quot;EUR&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;JPY&quot;]], rates1 = [2.0,3.0], pairs2 = [[&quot;JPY&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;CHF&quot;],[&quot;CHF&quot;,&quot;EUR&quot;]], rates2 = [4.0,5.0,6.0]</span></p> <p><strong>Output:</strong> <span class="example-io">720.00000</span></p> <p><strong>Explanation:</strong></p> <p>To get the maximum amount of <strong>EUR</strong>, starting with 1.0 <strong>EUR</strong>:</p> <ul> <li>On Day 1: <ul> <li>Convert <strong>EUR </strong>to <strong>USD</strong> to get 2.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>JPY</strong> to get 6.0 <strong>JPY</strong>.</li> </ul> </li> <li>On Day 2: <ul> <li>Convert <strong>JPY</strong> to <strong>USD</strong> to get 24.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>CHF</strong> to get 120.0 <strong>CHF</strong>.</li> <li>Finally, convert <strong>CHF</strong> to <strong>EUR</strong> to get 720.0 <strong>EUR</strong>.</li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;NGN&quot;, pairs1 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates1 = </span>[9.0]<span class="example-io">, pairs2 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates2 = </span>[6.0]</p> <p><strong>Output:</strong> 1.50000</p> <p><strong>Explanation:</strong></p> <p>Converting <strong>NGN</strong> to <strong>EUR</strong> on day 1 and <strong>EUR</strong> to <strong>NGN</strong> using the inverse rate on day 2 gives the maximum amount.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;USD&quot;, pairs1 = [[&quot;USD&quot;,&quot;EUR&quot;]], rates1 = [1.0], pairs2 = [[&quot;EUR&quot;,&quot;JPY&quot;]], rates2 = [10.0]</span></p> <p><strong>Output:</strong> <span class="example-io">1.00000</span></p> <p><strong>Explanation:</strong></p> <p>In this example, there is no need to make any conversions on either day.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= initialCurrency.length &lt;= 3</code></li> <li><code>initialCurrency</code> consists only of uppercase English letters.</li> <li><code>1 &lt;= n == pairs1.length &lt;= 10</code></li> <li><code>1 &lt;= m == pairs2.length &lt;= 10</code></li> <li><code>pairs1[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!-- notionvc: c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4 --></li> <li><code>pairs2[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!--{C}%3C!%2D%2D%20notionvc%3A%20c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4%20%2D%2D%3E--></li> <li><code>1 &lt;= startCurrency<sub>i</sub>.length, targetCurrency<sub>i</sub>.length &lt;= 3</code></li> <li><code>startCurrency<sub>i</sub></code> and <code>targetCurrency<sub>i</sub></code> consist only of uppercase English letters.</li> <li><code>rates1.length == n</code></li> <li><code>rates2.length == m</code></li> <li><code>1.0 &lt;= rates1[i], rates2[i] &lt;= 10.0</code></li> <li>The input is generated such that there are no contradictions or cycles in the conversion graphs for either day.</li> <li>The input is generated such that the output is <strong>at most</strong> <code>5 * 10<sup>10</sup></code>.</li> </ul>
Depth-First Search; Breadth-First Search; Graph; Array; String
Java
class Solution { public double maxAmount(String initialCurrency, List<List<String>> pairs1, double[] rates1, List<List<String>> pairs2, double[] rates2) { Map<String, Double> d1 = build(pairs1, rates1, initialCurrency); Map<String, Double> d2 = build(pairs2, rates2, initialCurrency); double ans = 0; for (Map.Entry<String, Double> entry : d2.entrySet()) { String currency = entry.getKey(); double rate = entry.getValue(); if (d1.containsKey(currency)) { ans = Math.max(ans, d1.get(currency) / rate); } } return ans; } private Map<String, Double> build(List<List<String>> pairs, double[] rates, String init) { Map<String, List<Pair<String, Double>>> g = new HashMap<>(); Map<String, Double> d = new HashMap<>(); for (int i = 0; i < pairs.size(); ++i) { String a = pairs.get(i).get(0); String b = pairs.get(i).get(1); double r = rates[i]; g.computeIfAbsent(a, k -> new ArrayList<>()).add(new Pair<>(b, r)); g.computeIfAbsent(b, k -> new ArrayList<>()).add(new Pair<>(a, 1 / r)); } dfs(g, d, init, 1.0); return d; } private void dfs( Map<String, List<Pair<String, Double>>> g, Map<String, Double> d, String a, double v) { if (d.containsKey(a)) { return; } d.put(a, v); for (Pair<String, Double> pair : g.getOrDefault(a, List.of())) { String b = pair.getKey(); double r = pair.getValue(); if (!d.containsKey(b)) { dfs(g, d, b, v * r); } } } }
3,387
Maximize Amount After Two Days of Conversions
Medium
<p>You are given a string <code>initialCurrency</code>, and you start with <code>1.0</code> of <code>initialCurrency</code>.</p> <p>You are also given four arrays with currency pairs (strings) and rates (real numbers):</p> <ul> <li><code>pairs1[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates1[i]</code> on <strong>day 1</strong>.</li> <li><code>pairs2[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates2[i]</code> on <strong>day 2</strong>.</li> <li>Also, each <code>targetCurrency</code> can be converted back to its corresponding <code>startCurrency</code> at a rate of <code>1 / rate</code>.</li> </ul> <p>You can perform <strong>any</strong> number of conversions, <strong>including zero</strong>, using <code>rates1</code> on day 1, <strong>followed</strong> by any number of additional conversions, <strong>including zero</strong>, using <code>rates2</code> on day 2.</p> <p>Return the <strong>maximum</strong> amount of <code>initialCurrency</code> you can have after performing any number of conversions on both days <strong>in order</strong>.</p> <p><strong>Note: </strong>Conversion rates are valid, and there will be no contradictions in the rates for either day. The rates for the days are independent of each other.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;EUR&quot;, pairs1 = [[&quot;EUR&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;JPY&quot;]], rates1 = [2.0,3.0], pairs2 = [[&quot;JPY&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;CHF&quot;],[&quot;CHF&quot;,&quot;EUR&quot;]], rates2 = [4.0,5.0,6.0]</span></p> <p><strong>Output:</strong> <span class="example-io">720.00000</span></p> <p><strong>Explanation:</strong></p> <p>To get the maximum amount of <strong>EUR</strong>, starting with 1.0 <strong>EUR</strong>:</p> <ul> <li>On Day 1: <ul> <li>Convert <strong>EUR </strong>to <strong>USD</strong> to get 2.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>JPY</strong> to get 6.0 <strong>JPY</strong>.</li> </ul> </li> <li>On Day 2: <ul> <li>Convert <strong>JPY</strong> to <strong>USD</strong> to get 24.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>CHF</strong> to get 120.0 <strong>CHF</strong>.</li> <li>Finally, convert <strong>CHF</strong> to <strong>EUR</strong> to get 720.0 <strong>EUR</strong>.</li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;NGN&quot;, pairs1 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates1 = </span>[9.0]<span class="example-io">, pairs2 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates2 = </span>[6.0]</p> <p><strong>Output:</strong> 1.50000</p> <p><strong>Explanation:</strong></p> <p>Converting <strong>NGN</strong> to <strong>EUR</strong> on day 1 and <strong>EUR</strong> to <strong>NGN</strong> using the inverse rate on day 2 gives the maximum amount.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;USD&quot;, pairs1 = [[&quot;USD&quot;,&quot;EUR&quot;]], rates1 = [1.0], pairs2 = [[&quot;EUR&quot;,&quot;JPY&quot;]], rates2 = [10.0]</span></p> <p><strong>Output:</strong> <span class="example-io">1.00000</span></p> <p><strong>Explanation:</strong></p> <p>In this example, there is no need to make any conversions on either day.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= initialCurrency.length &lt;= 3</code></li> <li><code>initialCurrency</code> consists only of uppercase English letters.</li> <li><code>1 &lt;= n == pairs1.length &lt;= 10</code></li> <li><code>1 &lt;= m == pairs2.length &lt;= 10</code></li> <li><code>pairs1[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!-- notionvc: c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4 --></li> <li><code>pairs2[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!--{C}%3C!%2D%2D%20notionvc%3A%20c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4%20%2D%2D%3E--></li> <li><code>1 &lt;= startCurrency<sub>i</sub>.length, targetCurrency<sub>i</sub>.length &lt;= 3</code></li> <li><code>startCurrency<sub>i</sub></code> and <code>targetCurrency<sub>i</sub></code> consist only of uppercase English letters.</li> <li><code>rates1.length == n</code></li> <li><code>rates2.length == m</code></li> <li><code>1.0 &lt;= rates1[i], rates2[i] &lt;= 10.0</code></li> <li>The input is generated such that there are no contradictions or cycles in the conversion graphs for either day.</li> <li>The input is generated such that the output is <strong>at most</strong> <code>5 * 10<sup>10</sup></code>.</li> </ul>
Depth-First Search; Breadth-First Search; Graph; Array; String
Python
class Solution: def maxAmount( self, initialCurrency: str, pairs1: List[List[str]], rates1: List[float], pairs2: List[List[str]], rates2: List[float], ) -> float: d1 = self.build(pairs1, rates1, initialCurrency) d2 = self.build(pairs2, rates2, initialCurrency) return max(d1.get(a, 0) / r2 for a, r2 in d2.items()) def build( self, pairs: List[List[str]], rates: List[float], init: str ) -> Dict[str, float]: def dfs(a: str, v: float): d[a] = v for b, r in g[a]: if b not in d: dfs(b, v * r) g = defaultdict(list) for (a, b), r in zip(pairs, rates): g[a].append((b, r)) g[b].append((a, 1 / r)) d = {} dfs(init, 1) return d
3,387
Maximize Amount After Two Days of Conversions
Medium
<p>You are given a string <code>initialCurrency</code>, and you start with <code>1.0</code> of <code>initialCurrency</code>.</p> <p>You are also given four arrays with currency pairs (strings) and rates (real numbers):</p> <ul> <li><code>pairs1[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates1[i]</code> on <strong>day 1</strong>.</li> <li><code>pairs2[i] = [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code> denotes that you can convert from <code>startCurrency<sub>i</sub></code> to <code>targetCurrency<sub>i</sub></code> at a rate of <code>rates2[i]</code> on <strong>day 2</strong>.</li> <li>Also, each <code>targetCurrency</code> can be converted back to its corresponding <code>startCurrency</code> at a rate of <code>1 / rate</code>.</li> </ul> <p>You can perform <strong>any</strong> number of conversions, <strong>including zero</strong>, using <code>rates1</code> on day 1, <strong>followed</strong> by any number of additional conversions, <strong>including zero</strong>, using <code>rates2</code> on day 2.</p> <p>Return the <strong>maximum</strong> amount of <code>initialCurrency</code> you can have after performing any number of conversions on both days <strong>in order</strong>.</p> <p><strong>Note: </strong>Conversion rates are valid, and there will be no contradictions in the rates for either day. The rates for the days are independent of each other.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;EUR&quot;, pairs1 = [[&quot;EUR&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;JPY&quot;]], rates1 = [2.0,3.0], pairs2 = [[&quot;JPY&quot;,&quot;USD&quot;],[&quot;USD&quot;,&quot;CHF&quot;],[&quot;CHF&quot;,&quot;EUR&quot;]], rates2 = [4.0,5.0,6.0]</span></p> <p><strong>Output:</strong> <span class="example-io">720.00000</span></p> <p><strong>Explanation:</strong></p> <p>To get the maximum amount of <strong>EUR</strong>, starting with 1.0 <strong>EUR</strong>:</p> <ul> <li>On Day 1: <ul> <li>Convert <strong>EUR </strong>to <strong>USD</strong> to get 2.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>JPY</strong> to get 6.0 <strong>JPY</strong>.</li> </ul> </li> <li>On Day 2: <ul> <li>Convert <strong>JPY</strong> to <strong>USD</strong> to get 24.0 <strong>USD</strong>.</li> <li>Convert <strong>USD</strong> to <strong>CHF</strong> to get 120.0 <strong>CHF</strong>.</li> <li>Finally, convert <strong>CHF</strong> to <strong>EUR</strong> to get 720.0 <strong>EUR</strong>.</li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;NGN&quot;, pairs1 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates1 = </span>[9.0]<span class="example-io">, pairs2 = </span>[[&quot;NGN&quot;,&quot;EUR&quot;]]<span class="example-io">, rates2 = </span>[6.0]</p> <p><strong>Output:</strong> 1.50000</p> <p><strong>Explanation:</strong></p> <p>Converting <strong>NGN</strong> to <strong>EUR</strong> on day 1 and <strong>EUR</strong> to <strong>NGN</strong> using the inverse rate on day 2 gives the maximum amount.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">initialCurrency = &quot;USD&quot;, pairs1 = [[&quot;USD&quot;,&quot;EUR&quot;]], rates1 = [1.0], pairs2 = [[&quot;EUR&quot;,&quot;JPY&quot;]], rates2 = [10.0]</span></p> <p><strong>Output:</strong> <span class="example-io">1.00000</span></p> <p><strong>Explanation:</strong></p> <p>In this example, there is no need to make any conversions on either day.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= initialCurrency.length &lt;= 3</code></li> <li><code>initialCurrency</code> consists only of uppercase English letters.</li> <li><code>1 &lt;= n == pairs1.length &lt;= 10</code></li> <li><code>1 &lt;= m == pairs2.length &lt;= 10</code></li> <li><code>pairs1[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!-- notionvc: c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4 --></li> <li><code>pairs2[i] == [startCurrency<sub>i</sub>, targetCurrency<sub>i</sub>]</code><!--{C}%3C!%2D%2D%20notionvc%3A%20c31b5bb8-4df6-4987-9bcd-6dff8a5f7cd4%20%2D%2D%3E--></li> <li><code>1 &lt;= startCurrency<sub>i</sub>.length, targetCurrency<sub>i</sub>.length &lt;= 3</code></li> <li><code>startCurrency<sub>i</sub></code> and <code>targetCurrency<sub>i</sub></code> consist only of uppercase English letters.</li> <li><code>rates1.length == n</code></li> <li><code>rates2.length == m</code></li> <li><code>1.0 &lt;= rates1[i], rates2[i] &lt;= 10.0</code></li> <li>The input is generated such that there are no contradictions or cycles in the conversion graphs for either day.</li> <li>The input is generated such that the output is <strong>at most</strong> <code>5 * 10<sup>10</sup></code>.</li> </ul>
Depth-First Search; Breadth-First Search; Graph; Array; String
TypeScript
class Pair { constructor( public key: string, public value: number, ) {} } function maxAmount( initialCurrency: string, pairs1: string[][], rates1: number[], pairs2: string[][], rates2: number[], ): number { const d1 = build(pairs1, rates1, initialCurrency); const d2 = build(pairs2, rates2, initialCurrency); let ans = 0; for (const [currency, rate] of Object.entries(d2)) { if (currency in d1) { ans = Math.max(ans, d1[currency] / rate); } } return ans; } function build(pairs: string[][], rates: number[], init: string): { [key: string]: number } { const g: { [key: string]: Pair[] } = {}; const d: { [key: string]: number } = {}; for (let i = 0; i < pairs.length; ++i) { const a = pairs[i][0]; const b = pairs[i][1]; const r = rates[i]; if (!g[a]) g[a] = []; if (!g[b]) g[b] = []; g[a].push(new Pair(b, r)); g[b].push(new Pair(a, 1 / r)); } dfs(g, d, init, 1.0); return d; } function dfs( g: { [key: string]: Pair[] }, d: { [key: string]: number }, a: string, v: number, ): void { if (a in d) { return; } d[a] = v; for (const pair of g[a] || []) { const b = pair.key; const r = pair.value; if (!(b in d)) { dfs(g, d, b, v * r); } } }
3,388
Count Beautiful Splits in an Array
Medium
<p>You are given an array <code>nums</code>.</p> <p>A split of an array <code>nums</code> is <strong>beautiful</strong> if:</p> <ol> <li>The array <code>nums</code> is split into three <span data-keyword="subarray-nonempty">subarrays</span>: <code>nums1</code>, <code>nums2</code>, and <code>nums3</code>, such that <code>nums</code> can be formed by concatenating <code>nums1</code>, <code>nums2</code>, and <code>nums3</code> in that order.</li> <li>The subarray <code>nums1</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums2</code> <strong>OR</strong> <code>nums2</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums3</code>.</li> </ol> <p>Return the <strong>number of ways</strong> you can make this split.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,2,1]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <p>The beautiful splits are:</p> <ol> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1,2]</code>, <code>nums3 = [1]</code>.</li> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1]</code>, <code>nums3 = [2,1]</code>.</li> </ol> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>There are 0 beautiful splits.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 5000</code></li> <li><code><font face="monospace">0 &lt;= nums[i] &lt;= 50</font></code></li> </ul>
Array; Dynamic Programming
C++
class Solution { public: int beautifulSplits(vector<int>& nums) { int n = nums.size(); vector<vector<int>> lcp(n + 1, vector<int>(n + 1, 0)); for (int i = n - 1; i >= 0; i--) { for (int j = n - 1; j > i; j--) { if (nums[i] == nums[j]) { lcp[i][j] = lcp[i + 1][j + 1] + 1; } } } int ans = 0; for (int i = 1; i < n - 1; i++) { for (int j = i + 1; j < n; j++) { bool a = (i <= j - i) && (lcp[0][i] >= i); bool b = (j - i <= n - j) && (lcp[i][j] >= j - i); if (a || b) { ans++; } } } return ans; } };
3,388
Count Beautiful Splits in an Array
Medium
<p>You are given an array <code>nums</code>.</p> <p>A split of an array <code>nums</code> is <strong>beautiful</strong> if:</p> <ol> <li>The array <code>nums</code> is split into three <span data-keyword="subarray-nonempty">subarrays</span>: <code>nums1</code>, <code>nums2</code>, and <code>nums3</code>, such that <code>nums</code> can be formed by concatenating <code>nums1</code>, <code>nums2</code>, and <code>nums3</code> in that order.</li> <li>The subarray <code>nums1</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums2</code> <strong>OR</strong> <code>nums2</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums3</code>.</li> </ol> <p>Return the <strong>number of ways</strong> you can make this split.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,2,1]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <p>The beautiful splits are:</p> <ol> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1,2]</code>, <code>nums3 = [1]</code>.</li> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1]</code>, <code>nums3 = [2,1]</code>.</li> </ol> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>There are 0 beautiful splits.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 5000</code></li> <li><code><font face="monospace">0 &lt;= nums[i] &lt;= 50</font></code></li> </ul>
Array; Dynamic Programming
Go
func beautifulSplits(nums []int) (ans int) { n := len(nums) lcp := make([][]int, n+1) for i := range lcp { lcp[i] = make([]int, n+1) } for i := n - 1; i >= 0; i-- { for j := n - 1; j > i; j-- { if nums[i] == nums[j] { lcp[i][j] = lcp[i+1][j+1] + 1 } } } for i := 1; i < n-1; i++ { for j := i + 1; j < n; j++ { a := i <= j-i && lcp[0][i] >= i b := j-i <= n-j && lcp[i][j] >= j-i if a || b { ans++ } } } return }
3,388
Count Beautiful Splits in an Array
Medium
<p>You are given an array <code>nums</code>.</p> <p>A split of an array <code>nums</code> is <strong>beautiful</strong> if:</p> <ol> <li>The array <code>nums</code> is split into three <span data-keyword="subarray-nonempty">subarrays</span>: <code>nums1</code>, <code>nums2</code>, and <code>nums3</code>, such that <code>nums</code> can be formed by concatenating <code>nums1</code>, <code>nums2</code>, and <code>nums3</code> in that order.</li> <li>The subarray <code>nums1</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums2</code> <strong>OR</strong> <code>nums2</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums3</code>.</li> </ol> <p>Return the <strong>number of ways</strong> you can make this split.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,2,1]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <p>The beautiful splits are:</p> <ol> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1,2]</code>, <code>nums3 = [1]</code>.</li> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1]</code>, <code>nums3 = [2,1]</code>.</li> </ol> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>There are 0 beautiful splits.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 5000</code></li> <li><code><font face="monospace">0 &lt;= nums[i] &lt;= 50</font></code></li> </ul>
Array; Dynamic Programming
Java
class Solution { public int beautifulSplits(int[] nums) { int n = nums.length; int[][] lcp = new int[n + 1][n + 1]; for (int i = n - 1; i >= 0; i--) { for (int j = n - 1; j > i; j--) { if (nums[i] == nums[j]) { lcp[i][j] = lcp[i + 1][j + 1] + 1; } } } int ans = 0; for (int i = 1; i < n - 1; i++) { for (int j = i + 1; j < n; j++) { boolean a = (i <= j - i) && (lcp[0][i] >= i); boolean b = (j - i <= n - j) && (lcp[i][j] >= j - i); if (a || b) { ans++; } } } return ans; } }
3,388
Count Beautiful Splits in an Array
Medium
<p>You are given an array <code>nums</code>.</p> <p>A split of an array <code>nums</code> is <strong>beautiful</strong> if:</p> <ol> <li>The array <code>nums</code> is split into three <span data-keyword="subarray-nonempty">subarrays</span>: <code>nums1</code>, <code>nums2</code>, and <code>nums3</code>, such that <code>nums</code> can be formed by concatenating <code>nums1</code>, <code>nums2</code>, and <code>nums3</code> in that order.</li> <li>The subarray <code>nums1</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums2</code> <strong>OR</strong> <code>nums2</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums3</code>.</li> </ol> <p>Return the <strong>number of ways</strong> you can make this split.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,2,1]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <p>The beautiful splits are:</p> <ol> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1,2]</code>, <code>nums3 = [1]</code>.</li> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1]</code>, <code>nums3 = [2,1]</code>.</li> </ol> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>There are 0 beautiful splits.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 5000</code></li> <li><code><font face="monospace">0 &lt;= nums[i] &lt;= 50</font></code></li> </ul>
Array; Dynamic Programming
Python
class Solution: def beautifulSplits(self, nums: List[int]) -> int: n = len(nums) lcp = [[0] * (n + 1) for _ in range(n + 1)] for i in range(n - 1, -1, -1): for j in range(n - 1, i - 1, -1): if nums[i] == nums[j]: lcp[i][j] = lcp[i + 1][j + 1] + 1 ans = 0 for i in range(1, n - 1): for j in range(i + 1, n): a = i <= j - i and lcp[0][i] >= i b = j - i <= n - j and lcp[i][j] >= j - i ans += int(a or b) return ans
3,388
Count Beautiful Splits in an Array
Medium
<p>You are given an array <code>nums</code>.</p> <p>A split of an array <code>nums</code> is <strong>beautiful</strong> if:</p> <ol> <li>The array <code>nums</code> is split into three <span data-keyword="subarray-nonempty">subarrays</span>: <code>nums1</code>, <code>nums2</code>, and <code>nums3</code>, such that <code>nums</code> can be formed by concatenating <code>nums1</code>, <code>nums2</code>, and <code>nums3</code> in that order.</li> <li>The subarray <code>nums1</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums2</code> <strong>OR</strong> <code>nums2</code> is a <span data-keyword="array-prefix">prefix</span> of <code>nums3</code>.</li> </ol> <p>Return the <strong>number of ways</strong> you can make this split.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,2,1]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <p>The beautiful splits are:</p> <ol> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1,2]</code>, <code>nums3 = [1]</code>.</li> <li>A split with <code>nums1 = [1]</code>, <code>nums2 = [1]</code>, <code>nums3 = [2,1]</code>.</li> </ol> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>There are 0 beautiful splits.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 5000</code></li> <li><code><font face="monospace">0 &lt;= nums[i] &lt;= 50</font></code></li> </ul>
Array; Dynamic Programming
TypeScript
function beautifulSplits(nums: number[]): number { const n = nums.length; const lcp: number[][] = Array.from({ length: n + 1 }, () => Array(n + 1).fill(0)); for (let i = n - 1; i >= 0; i--) { for (let j = n - 1; j > i; j--) { if (nums[i] === nums[j]) { lcp[i][j] = lcp[i + 1][j + 1] + 1; } } } let ans = 0; for (let i = 1; i < n - 1; i++) { for (let j = i + 1; j < n; j++) { const a = i <= j - i && lcp[0][i] >= i; const b = j - i <= n - j && lcp[i][j] >= j - i; if (a || b) { ans++; } } } return ans; }
3,390
Longest Team Pass Streak
Hard
<p>Table: <code>Teams</code></p> <pre> +-------------+---------+ | Column Name | Type | +-------------+---------+ | player_id | int | | team_name | varchar | +-------------+---------+ player_id is the unique key for this table. Each row contains the unique identifier for player and the name of one of the teams participating in that match. </pre> <p>Table: <code>Passes</code></p> <pre> +-------------+---------+ | Column Name | Type | +-------------+---------+ | pass_from | int | | time_stamp | varchar | | pass_to | int | +-------------+---------+ (pass_from, time_stamp) is the unique key for this table. pass_from is a foreign key to player_id from Teams table. Each row represents a pass made during a match, time_stamp represents the time in minutes (00:00-90:00) when the pass was made, pass_to is the player_id of the player receiving the pass. </pre> <p>Write a solution to find the <strong>longest successful pass streak</strong> for <strong>each team</strong> during the match. The rules are as follows:</p> <ul> <li>A successful pass streak is defined as consecutive passes where: <ul> <li>Both the <code>pass_from</code> and <code>pass_to</code> players belong to the same team</li> </ul> </li> <li>A streak breaks when either: <ul> <li>The pass is intercepted (received by a player from the opposing team)</li> </ul> </li> </ul> <p>Return <em>the result table ordered by</em> <code>team_name</code> <em>in <strong>ascending</strong> order</em>.</p> <p>The result format is in the following example.</p> <p>&nbsp;</p> <p><strong class="example">Example:</strong></p> <div class="example-block"> <p><strong>Input:</strong></p> <p>Teams table:</p> <pre> +-----------+-----------+ | player_id | team_name | +-----------+-----------+ | 1 | Arsenal | | 2 | Arsenal | | 3 | Arsenal | | 4 | Arsenal | | 5 | Chelsea | | 6 | Chelsea | | 7 | Chelsea | | 8 | Chelsea | +-----------+-----------+ </pre> <p>Passes table:</p> <pre> +-----------+------------+---------+ | pass_from | time_stamp | pass_to | +-----------+------------+---------+ | 1 | 00:05 | 2 | | 2 | 00:07 | 3 | | 3 | 00:08 | 4 | | 4 | 00:10 | 5 | | 6 | 00:15 | 7 | | 7 | 00:17 | 8 | | 8 | 00:20 | 6 | | 6 | 00:22 | 5 | | 1 | 00:25 | 2 | | 2 | 00:27 | 3 | +-----------+------------+---------+ </pre> <p><strong>Output:</strong></p> <pre> +-----------+----------------+ | team_name | longest_streak | +-----------+----------------+ | Arsenal | 3 | | Chelsea | 4 | +-----------+----------------+ </pre> <p><strong>Explanation:</strong></p> <ul> <li><strong>Arsenal</strong>&#39;s streaks: <ul> <li>First streak: 3 passes (1&rarr;2&rarr;3&rarr;4) ended when player 4 passed to Chelsea&#39;s player 5</li> <li>Second streak: 2 passes (1&rarr;2&rarr;3)</li> <li>Longest streak = 3</li> </ul> </li> <li><strong>Chelsea</strong>&#39;s streaks: <ul> <li>First streak: 3 passes (6&rarr;7&rarr;8&rarr;6&rarr;5)</li> <li>Longest streak = 4</li> </ul> </li> </ul> </div>
Database
SQL
WITH PassesWithTeams AS ( SELECT p.pass_from, p.pass_to, t1.team_name AS team_from, t2.team_name AS team_to, IF(t1.team_name = t2.team_name, 1, 0) same_team_flag, p.time_stamp FROM Passes p JOIN Teams t1 ON p.pass_from = t1.player_id JOIN Teams t2 ON p.pass_to = t2.player_id ), StreakGroups AS ( SELECT team_from AS team_name, time_stamp, same_team_flag, SUM( CASE WHEN same_team_flag = 0 THEN 1 ELSE 0 END ) OVER ( PARTITION BY team_from ORDER BY time_stamp ) AS group_id FROM PassesWithTeams ), StreakLengths AS ( SELECT team_name, group_id, COUNT(*) AS streak_length FROM StreakGroups WHERE same_team_flag = 1 GROUP BY 1, 2 ), LongestStreaks AS ( SELECT team_name, MAX(streak_length) AS longest_streak FROM StreakLengths GROUP BY 1 ) SELECT team_name, longest_streak FROM LongestStreaks ORDER BY 1;
3,391
Design a 3D Binary Matrix with Efficient Layer Tracking
Medium
<p>You are given a <code>n x n x n</code> <strong>binary</strong> 3D array <code>matrix</code>.</p> <p>Implement the <code>Matrix3D</code> class:</p> <ul> <li><code>Matrix3D(int n)</code> Initializes the object with the 3D binary array <code>matrix</code>, where <strong>all</strong> elements are initially set to 0.</li> <li><code>void setCell(int x, int y, int z)</code> Sets the value at <code>matrix[x][y][z]</code> to 1.</li> <li><code>void unsetCell(int x, int y, int z)</code> Sets the value at <code>matrix[x][y][z]</code> to 0.</li> <li><code>int largestMatrix()</code> Returns the index <code>x</code> where <code>matrix[x]</code> contains the most number of 1&#39;s. If there are multiple such indices, return the <strong>largest</strong> <code>x</code>.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;Matrix3D&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;]<br /> [[3], [0, 0, 0], [], [1, 1, 2], [], [0, 0, 1], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, 0, null, 1, null, 0] </span></p> <p><strong>Explanation</strong></p> Matrix3D matrix3D = new Matrix3D(3); // Initializes a <code>3 x 3 x 3</code> 3D array <code>matrix</code>, filled with all 0&#39;s.<br /> matrix3D.setCell(0, 0, 0); // Sets <code>matrix[0][0][0]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 0. <code>matrix[0]</code> has the most number of 1&#39;s.<br /> matrix3D.setCell(1, 1, 2); // Sets <code>matrix[1][1][2]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 1. <code>matrix[0]</code> and <code>matrix[1]</code> tie with the most number of 1&#39;s, but index 1 is bigger.<br /> matrix3D.setCell(0, 0, 1); // Sets <code>matrix[0][0][1]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 0. <code>matrix[0]</code> has the most number of 1&#39;s.</div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;Matrix3D&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;unsetCell&quot;, &quot;largestMatrix&quot;]<br /> [[4], [2, 1, 1], [], [2, 1, 1], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, 2, null, 3] </span></p> <p><strong>Explanation</strong></p> Matrix3D matrix3D = new Matrix3D(4); // Initializes a <code>4 x 4 x 4</code> 3D array <code>matrix</code>, filled with all 0&#39;s.<br /> matrix3D.setCell(2, 1, 1); // Sets <code>matrix[2][1][1]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 2. <code>matrix[2]</code> has the most number of 1&#39;s.<br /> matrix3D.unsetCell(2, 1, 1); // Sets <code>matrix[2][1][1]</code> to 0.<br /> matrix3D.largestMatrix(); // Returns 3. All indices from 0 to 3 tie with the same number of 1&#39;s, but index 3 is the biggest.</div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 100</code></li> <li><code>0 &lt;= x, y, z &lt; n</code></li> <li>At most <code>10<sup>5</sup></code> calls are made in total to <code>setCell</code> and <code>unsetCell</code>.</li> <li>At most <code>10<sup>4</sup></code> calls are made to <code>largestMatrix</code>.</li> </ul>
Design; Array; Hash Table; Matrix; Ordered Set; Heap (Priority Queue)
C++
class matrix3D { private: vector<vector<vector<int>>> g; vector<int> cnt; set<pair<int, int>> sl; public: matrix3D(int n) { g.resize(n, vector<vector<int>>(n, vector<int>(n, 0))); cnt.resize(n, 0); } void setCell(int x, int y, int z) { if (g[x][y][z] == 1) { return; } g[x][y][z] = 1; sl.erase({-cnt[x], -x}); cnt[x]++; sl.insert({-cnt[x], -x}); } void unsetCell(int x, int y, int z) { if (g[x][y][z] == 0) { return; } g[x][y][z] = 0; sl.erase({-cnt[x], -x}); cnt[x]--; if (cnt[x]) { sl.insert({-cnt[x], -x}); } } int largestMatrix() { return sl.empty() ? g.size() - 1 : -sl.begin()->second; } }; /** * Your matrix3D object will be instantiated and called as such: * matrix3D* obj = new matrix3D(n); * obj->setCell(x,y,z); * obj->unsetCell(x,y,z); * int param_3 = obj->largestMatrix(); */
3,391
Design a 3D Binary Matrix with Efficient Layer Tracking
Medium
<p>You are given a <code>n x n x n</code> <strong>binary</strong> 3D array <code>matrix</code>.</p> <p>Implement the <code>Matrix3D</code> class:</p> <ul> <li><code>Matrix3D(int n)</code> Initializes the object with the 3D binary array <code>matrix</code>, where <strong>all</strong> elements are initially set to 0.</li> <li><code>void setCell(int x, int y, int z)</code> Sets the value at <code>matrix[x][y][z]</code> to 1.</li> <li><code>void unsetCell(int x, int y, int z)</code> Sets the value at <code>matrix[x][y][z]</code> to 0.</li> <li><code>int largestMatrix()</code> Returns the index <code>x</code> where <code>matrix[x]</code> contains the most number of 1&#39;s. If there are multiple such indices, return the <strong>largest</strong> <code>x</code>.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;Matrix3D&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;]<br /> [[3], [0, 0, 0], [], [1, 1, 2], [], [0, 0, 1], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, 0, null, 1, null, 0] </span></p> <p><strong>Explanation</strong></p> Matrix3D matrix3D = new Matrix3D(3); // Initializes a <code>3 x 3 x 3</code> 3D array <code>matrix</code>, filled with all 0&#39;s.<br /> matrix3D.setCell(0, 0, 0); // Sets <code>matrix[0][0][0]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 0. <code>matrix[0]</code> has the most number of 1&#39;s.<br /> matrix3D.setCell(1, 1, 2); // Sets <code>matrix[1][1][2]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 1. <code>matrix[0]</code> and <code>matrix[1]</code> tie with the most number of 1&#39;s, but index 1 is bigger.<br /> matrix3D.setCell(0, 0, 1); // Sets <code>matrix[0][0][1]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 0. <code>matrix[0]</code> has the most number of 1&#39;s.</div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;Matrix3D&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;unsetCell&quot;, &quot;largestMatrix&quot;]<br /> [[4], [2, 1, 1], [], [2, 1, 1], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, 2, null, 3] </span></p> <p><strong>Explanation</strong></p> Matrix3D matrix3D = new Matrix3D(4); // Initializes a <code>4 x 4 x 4</code> 3D array <code>matrix</code>, filled with all 0&#39;s.<br /> matrix3D.setCell(2, 1, 1); // Sets <code>matrix[2][1][1]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 2. <code>matrix[2]</code> has the most number of 1&#39;s.<br /> matrix3D.unsetCell(2, 1, 1); // Sets <code>matrix[2][1][1]</code> to 0.<br /> matrix3D.largestMatrix(); // Returns 3. All indices from 0 to 3 tie with the same number of 1&#39;s, but index 3 is the biggest.</div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 100</code></li> <li><code>0 &lt;= x, y, z &lt; n</code></li> <li>At most <code>10<sup>5</sup></code> calls are made in total to <code>setCell</code> and <code>unsetCell</code>.</li> <li>At most <code>10<sup>4</sup></code> calls are made to <code>largestMatrix</code>.</li> </ul>
Design; Array; Hash Table; Matrix; Ordered Set; Heap (Priority Queue)
Java
class matrix3D { private final int[][][] g; private final int[] cnt; private final TreeSet<int[]> sl = new TreeSet<>((a, b) -> a[0] == b[0] ? b[1] - a[1] : b[0] - a[0]); public matrix3D(int n) { g = new int[n][n][n]; cnt = new int[n]; } public void setCell(int x, int y, int z) { if (g[x][y][z] == 1) { return; } g[x][y][z] = 1; sl.remove(new int[] {cnt[x], x}); cnt[x]++; sl.add(new int[] {cnt[x], x}); } public void unsetCell(int x, int y, int z) { if (g[x][y][z] == 0) { return; } g[x][y][z] = 0; sl.remove(new int[] {cnt[x], x}); cnt[x]--; if (cnt[x] > 0) { sl.add(new int[] {cnt[x], x}); } } public int largestMatrix() { return sl.isEmpty() ? g.length - 1 : sl.first()[1]; } } /** * Your matrix3D object will be instantiated and called as such: * matrix3D obj = new matrix3D(n); * obj.setCell(x,y,z); * obj.unsetCell(x,y,z); * int param_3 = obj.largestMatrix(); */
3,391
Design a 3D Binary Matrix with Efficient Layer Tracking
Medium
<p>You are given a <code>n x n x n</code> <strong>binary</strong> 3D array <code>matrix</code>.</p> <p>Implement the <code>Matrix3D</code> class:</p> <ul> <li><code>Matrix3D(int n)</code> Initializes the object with the 3D binary array <code>matrix</code>, where <strong>all</strong> elements are initially set to 0.</li> <li><code>void setCell(int x, int y, int z)</code> Sets the value at <code>matrix[x][y][z]</code> to 1.</li> <li><code>void unsetCell(int x, int y, int z)</code> Sets the value at <code>matrix[x][y][z]</code> to 0.</li> <li><code>int largestMatrix()</code> Returns the index <code>x</code> where <code>matrix[x]</code> contains the most number of 1&#39;s. If there are multiple such indices, return the <strong>largest</strong> <code>x</code>.</li> </ul> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;Matrix3D&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;]<br /> [[3], [0, 0, 0], [], [1, 1, 2], [], [0, 0, 1], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, 0, null, 1, null, 0] </span></p> <p><strong>Explanation</strong></p> Matrix3D matrix3D = new Matrix3D(3); // Initializes a <code>3 x 3 x 3</code> 3D array <code>matrix</code>, filled with all 0&#39;s.<br /> matrix3D.setCell(0, 0, 0); // Sets <code>matrix[0][0][0]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 0. <code>matrix[0]</code> has the most number of 1&#39;s.<br /> matrix3D.setCell(1, 1, 2); // Sets <code>matrix[1][1][2]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 1. <code>matrix[0]</code> and <code>matrix[1]</code> tie with the most number of 1&#39;s, but index 1 is bigger.<br /> matrix3D.setCell(0, 0, 1); // Sets <code>matrix[0][0][1]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 0. <code>matrix[0]</code> has the most number of 1&#39;s.</div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;Matrix3D&quot;, &quot;setCell&quot;, &quot;largestMatrix&quot;, &quot;unsetCell&quot;, &quot;largestMatrix&quot;]<br /> [[4], [2, 1, 1], [], [2, 1, 1], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, 2, null, 3] </span></p> <p><strong>Explanation</strong></p> Matrix3D matrix3D = new Matrix3D(4); // Initializes a <code>4 x 4 x 4</code> 3D array <code>matrix</code>, filled with all 0&#39;s.<br /> matrix3D.setCell(2, 1, 1); // Sets <code>matrix[2][1][1]</code> to 1.<br /> matrix3D.largestMatrix(); // Returns 2. <code>matrix[2]</code> has the most number of 1&#39;s.<br /> matrix3D.unsetCell(2, 1, 1); // Sets <code>matrix[2][1][1]</code> to 0.<br /> matrix3D.largestMatrix(); // Returns 3. All indices from 0 to 3 tie with the same number of 1&#39;s, but index 3 is the biggest.</div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 100</code></li> <li><code>0 &lt;= x, y, z &lt; n</code></li> <li>At most <code>10<sup>5</sup></code> calls are made in total to <code>setCell</code> and <code>unsetCell</code>.</li> <li>At most <code>10<sup>4</sup></code> calls are made to <code>largestMatrix</code>.</li> </ul>
Design; Array; Hash Table; Matrix; Ordered Set; Heap (Priority Queue)
Python
class matrix3D: def __init__(self, n: int): self.g = [[[0] * n for _ in range(n)] for _ in range(n)] self.cnt = [0] * n self.sl = SortedList(key=lambda x: (-x[0], -x[1])) def setCell(self, x: int, y: int, z: int) -> None: if self.g[x][y][z]: return self.g[x][y][z] = 1 self.sl.discard((self.cnt[x], x)) self.cnt[x] += 1 self.sl.add((self.cnt[x], x)) def unsetCell(self, x: int, y: int, z: int) -> None: if self.g[x][y][z] == 0: return self.g[x][y][z] = 0 self.sl.discard((self.cnt[x], x)) self.cnt[x] -= 1 if self.cnt[x]: self.sl.add((self.cnt[x], x)) def largestMatrix(self) -> int: return self.sl[0][1] if self.sl else len(self.g) - 1 # Your matrix3D object will be instantiated and called as such: # obj = matrix3D(n) # obj.setCell(x,y,z) # obj.unsetCell(x,y,z) # param_3 = obj.largestMatrix()
3,392
Count Subarrays of Length Three With a Condition
Easy
<p>Given an integer array <code>nums</code>, return the number of <span data-keyword="subarray-nonempty">subarrays</span> of length 3 such that the sum of the first and third numbers equals <em>exactly</em> half of the second number.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,1,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>Only the subarray <code>[1,4,1]</code> contains exactly 3 elements where the sum of the first and third numbers equals half the middle number.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,1]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p><code>[1,1,1]</code> is the only subarray of length 3. However, its first and third numbers do not add to half the middle number.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= nums.length &lt;= 100</code></li> <li><code><font face="monospace">-100 &lt;= nums[i] &lt;= 100</font></code></li> </ul>
Array
C++
class Solution { public: int countSubarrays(vector<int>& nums) { int ans = 0; for (int i = 1; i + 1 < nums.size(); ++i) { if ((nums[i - 1] + nums[i + 1]) * 2 == nums[i]) { ++ans; } } return ans; } };
3,392
Count Subarrays of Length Three With a Condition
Easy
<p>Given an integer array <code>nums</code>, return the number of <span data-keyword="subarray-nonempty">subarrays</span> of length 3 such that the sum of the first and third numbers equals <em>exactly</em> half of the second number.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,1,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>Only the subarray <code>[1,4,1]</code> contains exactly 3 elements where the sum of the first and third numbers equals half the middle number.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,1]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p><code>[1,1,1]</code> is the only subarray of length 3. However, its first and third numbers do not add to half the middle number.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= nums.length &lt;= 100</code></li> <li><code><font face="monospace">-100 &lt;= nums[i] &lt;= 100</font></code></li> </ul>
Array
Go
func countSubarrays(nums []int) (ans int) { for i := 1; i+1 < len(nums); i++ { if (nums[i-1]+nums[i+1])*2 == nums[i] { ans++ } } return }
3,392
Count Subarrays of Length Three With a Condition
Easy
<p>Given an integer array <code>nums</code>, return the number of <span data-keyword="subarray-nonempty">subarrays</span> of length 3 such that the sum of the first and third numbers equals <em>exactly</em> half of the second number.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,1,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>Only the subarray <code>[1,4,1]</code> contains exactly 3 elements where the sum of the first and third numbers equals half the middle number.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,1]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p><code>[1,1,1]</code> is the only subarray of length 3. However, its first and third numbers do not add to half the middle number.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= nums.length &lt;= 100</code></li> <li><code><font face="monospace">-100 &lt;= nums[i] &lt;= 100</font></code></li> </ul>
Array
Java
class Solution { public int countSubarrays(int[] nums) { int ans = 0; for (int i = 1; i + 1 < nums.length; ++i) { if ((nums[i - 1] + nums[i + 1]) * 2 == nums[i]) { ++ans; } } return ans; } }
3,392
Count Subarrays of Length Three With a Condition
Easy
<p>Given an integer array <code>nums</code>, return the number of <span data-keyword="subarray-nonempty">subarrays</span> of length 3 such that the sum of the first and third numbers equals <em>exactly</em> half of the second number.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,1,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>Only the subarray <code>[1,4,1]</code> contains exactly 3 elements where the sum of the first and third numbers equals half the middle number.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,1]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p><code>[1,1,1]</code> is the only subarray of length 3. However, its first and third numbers do not add to half the middle number.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= nums.length &lt;= 100</code></li> <li><code><font face="monospace">-100 &lt;= nums[i] &lt;= 100</font></code></li> </ul>
Array
Python
class Solution: def countSubarrays(self, nums: List[int]) -> int: return sum( (nums[i - 1] + nums[i + 1]) * 2 == nums[i] for i in range(1, len(nums) - 1) )
3,392
Count Subarrays of Length Three With a Condition
Easy
<p>Given an integer array <code>nums</code>, return the number of <span data-keyword="subarray-nonempty">subarrays</span> of length 3 such that the sum of the first and third numbers equals <em>exactly</em> half of the second number.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,1,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>Only the subarray <code>[1,4,1]</code> contains exactly 3 elements where the sum of the first and third numbers equals half the middle number.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,1]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p><code>[1,1,1]</code> is the only subarray of length 3. However, its first and third numbers do not add to half the middle number.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= nums.length &lt;= 100</code></li> <li><code><font face="monospace">-100 &lt;= nums[i] &lt;= 100</font></code></li> </ul>
Array
Rust
impl Solution { pub fn count_subarrays(nums: Vec<i32>) -> i32 { let mut ans = 0; for i in 1..nums.len() - 1 { if (nums[i - 1] + nums[i + 1]) * 2 == nums[i] { ans += 1; } } ans } }
3,392
Count Subarrays of Length Three With a Condition
Easy
<p>Given an integer array <code>nums</code>, return the number of <span data-keyword="subarray-nonempty">subarrays</span> of length 3 such that the sum of the first and third numbers equals <em>exactly</em> half of the second number.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,1,4,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>Only the subarray <code>[1,4,1]</code> contains exactly 3 elements where the sum of the first and third numbers equals half the middle number.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,1,1]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p><code>[1,1,1]</code> is the only subarray of length 3. However, its first and third numbers do not add to half the middle number.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= nums.length &lt;= 100</code></li> <li><code><font face="monospace">-100 &lt;= nums[i] &lt;= 100</font></code></li> </ul>
Array
TypeScript
function countSubarrays(nums: number[]): number { let ans: number = 0; for (let i = 1; i + 1 < nums.length; ++i) { if ((nums[i - 1] + nums[i + 1]) * 2 === nums[i]) { ++ans; } } return ans; }
3,394
Check if Grid can be Cut into Sections
Medium
<p>You are given an integer <code>n</code> representing the dimensions of an <code>n x n</code><!-- notionvc: fa9fe4ed-dff8-4410-8196-346f2d430795 --> grid, with the origin at the bottom-left corner of the grid. You are also given a 2D array of coordinates <code>rectangles</code>, where <code>rectangles[i]</code> is in the form <code>[start<sub>x</sub>, start<sub>y</sub>, end<sub>x</sub>, end<sub>y</sub>]</code>, representing a rectangle on the grid. Each rectangle is defined as follows:</p> <ul> <li><code>(start<sub>x</sub>, start<sub>y</sub>)</code>: The bottom-left corner of the rectangle.</li> <li><code>(end<sub>x</sub>, end<sub>y</sub>)</code>: The top-right corner of the rectangle.</li> </ul> <p><strong>Note </strong>that the rectangles do not overlap. Your task is to determine if it is possible to make <strong>either two horizontal or two vertical cuts</strong> on the grid such that:</p> <ul> <li>Each of the three resulting sections formed by the cuts contains <strong>at least</strong> one rectangle.</li> <li>Every rectangle belongs to <strong>exactly</strong> one section.</li> </ul> <p>Return <code>true</code> if such cuts can be made; otherwise, return <code>false</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, rectangles = [[1,0,5,2],[0,2,2,4],[3,2,5,3],[0,4,4,5]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tt1drawio.png" style="width: 285px; height: 280px;" /></p> <p>The grid is shown in the diagram. We can make horizontal cuts at <code>y = 2</code> and <code>y = 4</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,0,1,1],[2,0,3,4],[0,2,2,3],[3,0,4,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tc2drawio.png" style="width: 240px; height: 240px;" /></p> <p>We can make vertical cuts at <code>x = 2</code> and <code>x = 3</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,2,2,4],[1,0,3,2],[2,2,3,4],[3,0,4,2],[3,2,4,4]]</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>We cannot make two horizontal or two vertical cuts that satisfy the conditions. Hence, output is false.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= n &lt;= 10<sup>9</sup></code></li> <li><code>3 &lt;= rectangles.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= rectangles[i][0] &lt; rectangles[i][2] &lt;= n</code></li> <li><code>0 &lt;= rectangles[i][1] &lt; rectangles[i][3] &lt;= n</code></li> <li>No two rectangles overlap.</li> </ul>
Array; Sorting
C++
class Solution { #define pii pair<int, int> bool countLineIntersections(vector<pii>& coordinates) { int lines = 0; int overlap = 0; for (int i = 0; i < coordinates.size(); ++i) { if (coordinates[i].second == 0) overlap--; else overlap++; if (overlap == 0) lines++; } return lines >= 3; } public: bool checkValidCuts(int n, vector<vector<int>>& rectangles) { vector<pii> y_cordinates, x_cordinates; for (auto& rectangle : rectangles) { y_cordinates.push_back(make_pair(rectangle[1], 1)); y_cordinates.push_back(make_pair(rectangle[3], 0)); x_cordinates.push_back(make_pair(rectangle[0], 1)); x_cordinates.push_back(make_pair(rectangle[2], 0)); } sort(y_cordinates.begin(), y_cordinates.end()); sort(x_cordinates.begin(), x_cordinates.end()); // Line-Sweep on x and y cordinates return (countLineIntersections(y_cordinates) or countLineIntersections(x_cordinates)); } };
3,394
Check if Grid can be Cut into Sections
Medium
<p>You are given an integer <code>n</code> representing the dimensions of an <code>n x n</code><!-- notionvc: fa9fe4ed-dff8-4410-8196-346f2d430795 --> grid, with the origin at the bottom-left corner of the grid. You are also given a 2D array of coordinates <code>rectangles</code>, where <code>rectangles[i]</code> is in the form <code>[start<sub>x</sub>, start<sub>y</sub>, end<sub>x</sub>, end<sub>y</sub>]</code>, representing a rectangle on the grid. Each rectangle is defined as follows:</p> <ul> <li><code>(start<sub>x</sub>, start<sub>y</sub>)</code>: The bottom-left corner of the rectangle.</li> <li><code>(end<sub>x</sub>, end<sub>y</sub>)</code>: The top-right corner of the rectangle.</li> </ul> <p><strong>Note </strong>that the rectangles do not overlap. Your task is to determine if it is possible to make <strong>either two horizontal or two vertical cuts</strong> on the grid such that:</p> <ul> <li>Each of the three resulting sections formed by the cuts contains <strong>at least</strong> one rectangle.</li> <li>Every rectangle belongs to <strong>exactly</strong> one section.</li> </ul> <p>Return <code>true</code> if such cuts can be made; otherwise, return <code>false</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, rectangles = [[1,0,5,2],[0,2,2,4],[3,2,5,3],[0,4,4,5]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tt1drawio.png" style="width: 285px; height: 280px;" /></p> <p>The grid is shown in the diagram. We can make horizontal cuts at <code>y = 2</code> and <code>y = 4</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,0,1,1],[2,0,3,4],[0,2,2,3],[3,0,4,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tc2drawio.png" style="width: 240px; height: 240px;" /></p> <p>We can make vertical cuts at <code>x = 2</code> and <code>x = 3</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,2,2,4],[1,0,3,2],[2,2,3,4],[3,0,4,2],[3,2,4,4]]</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>We cannot make two horizontal or two vertical cuts that satisfy the conditions. Hence, output is false.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= n &lt;= 10<sup>9</sup></code></li> <li><code>3 &lt;= rectangles.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= rectangles[i][0] &lt; rectangles[i][2] &lt;= n</code></li> <li><code>0 &lt;= rectangles[i][1] &lt; rectangles[i][3] &lt;= n</code></li> <li>No two rectangles overlap.</li> </ul>
Array; Sorting
Go
type Pair struct { val int typ int // 1 = start, 0 = end } func countLineIntersections(coords []Pair) bool { lines := 0 overlap := 0 for _, p := range coords { if p.typ == 0 { overlap-- } else { overlap++ } if overlap == 0 { lines++ } } return lines >= 3 } func checkValidCuts(n int, rectangles [][]int) bool { var xCoords []Pair var yCoords []Pair for _, rect := range rectangles { x1, y1, x2, y2 := rect[0], rect[1], rect[2], rect[3] yCoords = append(yCoords, Pair{y1, 1}) // start yCoords = append(yCoords, Pair{y2, 0}) // end xCoords = append(xCoords, Pair{x1, 1}) xCoords = append(xCoords, Pair{x2, 0}) } sort.Slice(yCoords, func(i, j int) bool { if yCoords[i].val == yCoords[j].val { return yCoords[i].typ < yCoords[j].typ // end before start } return yCoords[i].val < yCoords[j].val }) sort.Slice(xCoords, func(i, j int) bool { if xCoords[i].val == xCoords[j].val { return xCoords[i].typ < xCoords[j].typ } return xCoords[i].val < xCoords[j].val }) return countLineIntersections(yCoords) || countLineIntersections(xCoords) }
3,394
Check if Grid can be Cut into Sections
Medium
<p>You are given an integer <code>n</code> representing the dimensions of an <code>n x n</code><!-- notionvc: fa9fe4ed-dff8-4410-8196-346f2d430795 --> grid, with the origin at the bottom-left corner of the grid. You are also given a 2D array of coordinates <code>rectangles</code>, where <code>rectangles[i]</code> is in the form <code>[start<sub>x</sub>, start<sub>y</sub>, end<sub>x</sub>, end<sub>y</sub>]</code>, representing a rectangle on the grid. Each rectangle is defined as follows:</p> <ul> <li><code>(start<sub>x</sub>, start<sub>y</sub>)</code>: The bottom-left corner of the rectangle.</li> <li><code>(end<sub>x</sub>, end<sub>y</sub>)</code>: The top-right corner of the rectangle.</li> </ul> <p><strong>Note </strong>that the rectangles do not overlap. Your task is to determine if it is possible to make <strong>either two horizontal or two vertical cuts</strong> on the grid such that:</p> <ul> <li>Each of the three resulting sections formed by the cuts contains <strong>at least</strong> one rectangle.</li> <li>Every rectangle belongs to <strong>exactly</strong> one section.</li> </ul> <p>Return <code>true</code> if such cuts can be made; otherwise, return <code>false</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, rectangles = [[1,0,5,2],[0,2,2,4],[3,2,5,3],[0,4,4,5]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tt1drawio.png" style="width: 285px; height: 280px;" /></p> <p>The grid is shown in the diagram. We can make horizontal cuts at <code>y = 2</code> and <code>y = 4</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,0,1,1],[2,0,3,4],[0,2,2,3],[3,0,4,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tc2drawio.png" style="width: 240px; height: 240px;" /></p> <p>We can make vertical cuts at <code>x = 2</code> and <code>x = 3</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,2,2,4],[1,0,3,2],[2,2,3,4],[3,0,4,2],[3,2,4,4]]</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>We cannot make two horizontal or two vertical cuts that satisfy the conditions. Hence, output is false.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= n &lt;= 10<sup>9</sup></code></li> <li><code>3 &lt;= rectangles.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= rectangles[i][0] &lt; rectangles[i][2] &lt;= n</code></li> <li><code>0 &lt;= rectangles[i][1] &lt; rectangles[i][3] &lt;= n</code></li> <li>No two rectangles overlap.</li> </ul>
Array; Sorting
Java
class Solution { // Helper class to mimic C++ pair<int, int> static class Pair { int value; int type; Pair(int value, int type) { this.value = value; this.type = type; } } private boolean countLineIntersections(List<Pair> coordinates) { int lines = 0; int overlap = 0; for (Pair coord : coordinates) { if (coord.type == 0) { overlap--; } else { overlap++; } if (overlap == 0) { lines++; } } return lines >= 3; } public boolean checkValidCuts(int n, int[][] rectangles) { List<Pair> yCoordinates = new ArrayList<>(); List<Pair> xCoordinates = new ArrayList<>(); for (int[] rectangle : rectangles) { // rectangle = [x1, y1, x2, y2] yCoordinates.add(new Pair(rectangle[1], 1)); // y1, start yCoordinates.add(new Pair(rectangle[3], 0)); // y2, end xCoordinates.add(new Pair(rectangle[0], 1)); // x1, start xCoordinates.add(new Pair(rectangle[2], 0)); // x2, end } Comparator<Pair> comparator = (a, b) -> { if (a.value != b.value) return Integer.compare(a.value, b.value); return Integer.compare(a.type, b.type); // End (0) before Start (1) }; Collections.sort(yCoordinates, comparator); Collections.sort(xCoordinates, comparator); return countLineIntersections(yCoordinates) || countLineIntersections(xCoordinates); } }
3,394
Check if Grid can be Cut into Sections
Medium
<p>You are given an integer <code>n</code> representing the dimensions of an <code>n x n</code><!-- notionvc: fa9fe4ed-dff8-4410-8196-346f2d430795 --> grid, with the origin at the bottom-left corner of the grid. You are also given a 2D array of coordinates <code>rectangles</code>, where <code>rectangles[i]</code> is in the form <code>[start<sub>x</sub>, start<sub>y</sub>, end<sub>x</sub>, end<sub>y</sub>]</code>, representing a rectangle on the grid. Each rectangle is defined as follows:</p> <ul> <li><code>(start<sub>x</sub>, start<sub>y</sub>)</code>: The bottom-left corner of the rectangle.</li> <li><code>(end<sub>x</sub>, end<sub>y</sub>)</code>: The top-right corner of the rectangle.</li> </ul> <p><strong>Note </strong>that the rectangles do not overlap. Your task is to determine if it is possible to make <strong>either two horizontal or two vertical cuts</strong> on the grid such that:</p> <ul> <li>Each of the three resulting sections formed by the cuts contains <strong>at least</strong> one rectangle.</li> <li>Every rectangle belongs to <strong>exactly</strong> one section.</li> </ul> <p>Return <code>true</code> if such cuts can be made; otherwise, return <code>false</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, rectangles = [[1,0,5,2],[0,2,2,4],[3,2,5,3],[0,4,4,5]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tt1drawio.png" style="width: 285px; height: 280px;" /></p> <p>The grid is shown in the diagram. We can make horizontal cuts at <code>y = 2</code> and <code>y = 4</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,0,1,1],[2,0,3,4],[0,2,2,3],[3,0,4,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tc2drawio.png" style="width: 240px; height: 240px;" /></p> <p>We can make vertical cuts at <code>x = 2</code> and <code>x = 3</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,2,2,4],[1,0,3,2],[2,2,3,4],[3,0,4,2],[3,2,4,4]]</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>We cannot make two horizontal or two vertical cuts that satisfy the conditions. Hence, output is false.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= n &lt;= 10<sup>9</sup></code></li> <li><code>3 &lt;= rectangles.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= rectangles[i][0] &lt; rectangles[i][2] &lt;= n</code></li> <li><code>0 &lt;= rectangles[i][1] &lt; rectangles[i][3] &lt;= n</code></li> <li>No two rectangles overlap.</li> </ul>
Array; Sorting
JavaScript
function checkValidCuts(n, rectangles) { const check = (arr, getVals) => { let [c, longest] = [3, 0]; for (const x of arr) { const [start, end] = getVals(x); if (start < longest) { longest = Math.max(longest, end); } else { longest = end; if (--c === 0) return true; } } return false; }; const sortByX = ([a], [b]) => a - b; const sortByY = ([, a], [, b]) => a - b; const getX = ([x1, , x2]) => [x1, x2]; const getY = ([, y1, , y2]) => [y1, y2]; return check(rectangles.toSorted(sortByX), getX) || check(rectangles.toSorted(sortByY), getY); }
3,394
Check if Grid can be Cut into Sections
Medium
<p>You are given an integer <code>n</code> representing the dimensions of an <code>n x n</code><!-- notionvc: fa9fe4ed-dff8-4410-8196-346f2d430795 --> grid, with the origin at the bottom-left corner of the grid. You are also given a 2D array of coordinates <code>rectangles</code>, where <code>rectangles[i]</code> is in the form <code>[start<sub>x</sub>, start<sub>y</sub>, end<sub>x</sub>, end<sub>y</sub>]</code>, representing a rectangle on the grid. Each rectangle is defined as follows:</p> <ul> <li><code>(start<sub>x</sub>, start<sub>y</sub>)</code>: The bottom-left corner of the rectangle.</li> <li><code>(end<sub>x</sub>, end<sub>y</sub>)</code>: The top-right corner of the rectangle.</li> </ul> <p><strong>Note </strong>that the rectangles do not overlap. Your task is to determine if it is possible to make <strong>either two horizontal or two vertical cuts</strong> on the grid such that:</p> <ul> <li>Each of the three resulting sections formed by the cuts contains <strong>at least</strong> one rectangle.</li> <li>Every rectangle belongs to <strong>exactly</strong> one section.</li> </ul> <p>Return <code>true</code> if such cuts can be made; otherwise, return <code>false</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, rectangles = [[1,0,5,2],[0,2,2,4],[3,2,5,3],[0,4,4,5]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tt1drawio.png" style="width: 285px; height: 280px;" /></p> <p>The grid is shown in the diagram. We can make horizontal cuts at <code>y = 2</code> and <code>y = 4</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,0,1,1],[2,0,3,4],[0,2,2,3],[3,0,4,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tc2drawio.png" style="width: 240px; height: 240px;" /></p> <p>We can make vertical cuts at <code>x = 2</code> and <code>x = 3</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,2,2,4],[1,0,3,2],[2,2,3,4],[3,0,4,2],[3,2,4,4]]</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>We cannot make two horizontal or two vertical cuts that satisfy the conditions. Hence, output is false.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= n &lt;= 10<sup>9</sup></code></li> <li><code>3 &lt;= rectangles.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= rectangles[i][0] &lt; rectangles[i][2] &lt;= n</code></li> <li><code>0 &lt;= rectangles[i][1] &lt; rectangles[i][3] &lt;= n</code></li> <li>No two rectangles overlap.</li> </ul>
Array; Sorting
Python
class Solution: def countLineIntersections(self, coordinates: List[tuple[int, int]]) -> bool: lines = 0 overlap = 0 for value, marker in coordinates: if marker == 0: overlap -= 1 else: overlap += 1 if overlap == 0: lines += 1 return lines >= 3 def checkValidCuts(self, n: int, rectangles: List[List[int]]) -> bool: y_coordinates = [] x_coordinates = [] for rect in rectangles: x1, y1, x2, y2 = rect y_coordinates.append((y1, 1)) # start y_coordinates.append((y2, 0)) # end x_coordinates.append((x1, 1)) # start x_coordinates.append((x2, 0)) # end # Sort by coordinate value, and for tie, put end (0) before start (1) y_coordinates.sort(key=lambda x: (x[0], x[1])) x_coordinates.sort(key=lambda x: (x[0], x[1])) return self.countLineIntersections( y_coordinates ) or self.countLineIntersections(x_coordinates)
3,394
Check if Grid can be Cut into Sections
Medium
<p>You are given an integer <code>n</code> representing the dimensions of an <code>n x n</code><!-- notionvc: fa9fe4ed-dff8-4410-8196-346f2d430795 --> grid, with the origin at the bottom-left corner of the grid. You are also given a 2D array of coordinates <code>rectangles</code>, where <code>rectangles[i]</code> is in the form <code>[start<sub>x</sub>, start<sub>y</sub>, end<sub>x</sub>, end<sub>y</sub>]</code>, representing a rectangle on the grid. Each rectangle is defined as follows:</p> <ul> <li><code>(start<sub>x</sub>, start<sub>y</sub>)</code>: The bottom-left corner of the rectangle.</li> <li><code>(end<sub>x</sub>, end<sub>y</sub>)</code>: The top-right corner of the rectangle.</li> </ul> <p><strong>Note </strong>that the rectangles do not overlap. Your task is to determine if it is possible to make <strong>either two horizontal or two vertical cuts</strong> on the grid such that:</p> <ul> <li>Each of the three resulting sections formed by the cuts contains <strong>at least</strong> one rectangle.</li> <li>Every rectangle belongs to <strong>exactly</strong> one section.</li> </ul> <p>Return <code>true</code> if such cuts can be made; otherwise, return <code>false</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, rectangles = [[1,0,5,2],[0,2,2,4],[3,2,5,3],[0,4,4,5]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tt1drawio.png" style="width: 285px; height: 280px;" /></p> <p>The grid is shown in the diagram. We can make horizontal cuts at <code>y = 2</code> and <code>y = 4</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,0,1,1],[2,0,3,4],[0,2,2,3],[3,0,4,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p><img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3300-3399/3394.Check%20if%20Grid%20can%20be%20Cut%20into%20Sections/images/tc2drawio.png" style="width: 240px; height: 240px;" /></p> <p>We can make vertical cuts at <code>x = 2</code> and <code>x = 3</code>. Hence, output is true.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, rectangles = [[0,2,2,4],[1,0,3,2],[2,2,3,4],[3,0,4,2],[3,2,4,4]]</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>We cannot make two horizontal or two vertical cuts that satisfy the conditions. Hence, output is false.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 &lt;= n &lt;= 10<sup>9</sup></code></li> <li><code>3 &lt;= rectangles.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= rectangles[i][0] &lt; rectangles[i][2] &lt;= n</code></li> <li><code>0 &lt;= rectangles[i][1] &lt; rectangles[i][3] &lt;= n</code></li> <li>No two rectangles overlap.</li> </ul>
Array; Sorting
TypeScript
function checkValidCuts(n: number, rectangles: number[][]): boolean { const check = (arr: number[][], getVals: (x: number[]) => number[]) => { let [c, longest] = [3, 0]; for (const x of arr) { const [start, end] = getVals(x); if (start < longest) { longest = Math.max(longest, end); } else { longest = end; if (--c === 0) return true; } } return false; }; const sortByX = ([a]: number[], [b]: number[]) => a - b; const sortByY = ([, a]: number[], [, b]: number[]) => a - b; const getX = ([x1, , x2]: number[]) => [x1, x2]; const getY = ([, y1, , y2]: number[]) => [y1, y2]; return check(rectangles.toSorted(sortByX), getX) || check(rectangles.toSorted(sortByY), getY); }
3,396
Minimum Number of Operations to Make Elements in Array Distinct
Easy
<p>You are given an integer array <code>nums</code>. You need to ensure that the elements in the array are <strong>distinct</strong>. To achieve this, you can perform the following operation any number of times:</p> <ul> <li>Remove 3 elements from the beginning of the array. If the array has fewer than 3 elements, remove all remaining elements.</li> </ul> <p><strong>Note</strong> that an empty array is considered to have distinct elements. Return the <strong>minimum</strong> number of operations needed to make the elements in the array distinct.<!-- notionvc: 210ee4f2-90af-4cdf-8dbc-96d1fa8f67c7 --></p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,2,3,3,5,7]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 2, 3, 3, 5, 7]</code>.</li> <li>In the second operation, the next 3 elements are removed, resulting in the array <code>[3, 5, 7]</code>, which has distinct elements.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,5,6,4,4]</span></p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 4]</code>.</li> <li>In the second operation, all remaining elements are removed, resulting in an empty array.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [6,7,8,9]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>The array already contains distinct elements. Therefore, the answer is 0.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 100</code></li> <li><code>1 &lt;= nums[i] &lt;= 100</code></li> </ul>
Array; Hash Table
C++
class Solution { public: int minimumOperations(vector<int>& nums) { unordered_set<int> s; for (int i = nums.size() - 1; ~i; --i) { if (s.contains(nums[i])) { return i / 3 + 1; } s.insert(nums[i]); } return 0; } };
3,396
Minimum Number of Operations to Make Elements in Array Distinct
Easy
<p>You are given an integer array <code>nums</code>. You need to ensure that the elements in the array are <strong>distinct</strong>. To achieve this, you can perform the following operation any number of times:</p> <ul> <li>Remove 3 elements from the beginning of the array. If the array has fewer than 3 elements, remove all remaining elements.</li> </ul> <p><strong>Note</strong> that an empty array is considered to have distinct elements. Return the <strong>minimum</strong> number of operations needed to make the elements in the array distinct.<!-- notionvc: 210ee4f2-90af-4cdf-8dbc-96d1fa8f67c7 --></p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,2,3,3,5,7]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 2, 3, 3, 5, 7]</code>.</li> <li>In the second operation, the next 3 elements are removed, resulting in the array <code>[3, 5, 7]</code>, which has distinct elements.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,5,6,4,4]</span></p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 4]</code>.</li> <li>In the second operation, all remaining elements are removed, resulting in an empty array.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [6,7,8,9]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>The array already contains distinct elements. Therefore, the answer is 0.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 100</code></li> <li><code>1 &lt;= nums[i] &lt;= 100</code></li> </ul>
Array; Hash Table
Go
func minimumOperations(nums []int) int { s := map[int]bool{} for i := len(nums) - 1; i >= 0; i-- { if s[nums[i]] { return i/3 + 1 } s[nums[i]] = true } return 0 }
3,396
Minimum Number of Operations to Make Elements in Array Distinct
Easy
<p>You are given an integer array <code>nums</code>. You need to ensure that the elements in the array are <strong>distinct</strong>. To achieve this, you can perform the following operation any number of times:</p> <ul> <li>Remove 3 elements from the beginning of the array. If the array has fewer than 3 elements, remove all remaining elements.</li> </ul> <p><strong>Note</strong> that an empty array is considered to have distinct elements. Return the <strong>minimum</strong> number of operations needed to make the elements in the array distinct.<!-- notionvc: 210ee4f2-90af-4cdf-8dbc-96d1fa8f67c7 --></p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,2,3,3,5,7]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 2, 3, 3, 5, 7]</code>.</li> <li>In the second operation, the next 3 elements are removed, resulting in the array <code>[3, 5, 7]</code>, which has distinct elements.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,5,6,4,4]</span></p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 4]</code>.</li> <li>In the second operation, all remaining elements are removed, resulting in an empty array.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [6,7,8,9]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>The array already contains distinct elements. Therefore, the answer is 0.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 100</code></li> <li><code>1 &lt;= nums[i] &lt;= 100</code></li> </ul>
Array; Hash Table
Java
class Solution { public int minimumOperations(int[] nums) { Set<Integer> s = new HashSet<>(); for (int i = nums.length - 1; i >= 0; --i) { if (!s.add(nums[i])) { return i / 3 + 1; } } return 0; } }
3,396
Minimum Number of Operations to Make Elements in Array Distinct
Easy
<p>You are given an integer array <code>nums</code>. You need to ensure that the elements in the array are <strong>distinct</strong>. To achieve this, you can perform the following operation any number of times:</p> <ul> <li>Remove 3 elements from the beginning of the array. If the array has fewer than 3 elements, remove all remaining elements.</li> </ul> <p><strong>Note</strong> that an empty array is considered to have distinct elements. Return the <strong>minimum</strong> number of operations needed to make the elements in the array distinct.<!-- notionvc: 210ee4f2-90af-4cdf-8dbc-96d1fa8f67c7 --></p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,2,3,3,5,7]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 2, 3, 3, 5, 7]</code>.</li> <li>In the second operation, the next 3 elements are removed, resulting in the array <code>[3, 5, 7]</code>, which has distinct elements.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,5,6,4,4]</span></p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 4]</code>.</li> <li>In the second operation, all remaining elements are removed, resulting in an empty array.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [6,7,8,9]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>The array already contains distinct elements. Therefore, the answer is 0.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 100</code></li> <li><code>1 &lt;= nums[i] &lt;= 100</code></li> </ul>
Array; Hash Table
Python
class Solution: def minimumOperations(self, nums: List[int]) -> int: s = set() for i in range(len(nums) - 1, -1, -1): if nums[i] in s: return i // 3 + 1 s.add(nums[i]) return 0
3,396
Minimum Number of Operations to Make Elements in Array Distinct
Easy
<p>You are given an integer array <code>nums</code>. You need to ensure that the elements in the array are <strong>distinct</strong>. To achieve this, you can perform the following operation any number of times:</p> <ul> <li>Remove 3 elements from the beginning of the array. If the array has fewer than 3 elements, remove all remaining elements.</li> </ul> <p><strong>Note</strong> that an empty array is considered to have distinct elements. Return the <strong>minimum</strong> number of operations needed to make the elements in the array distinct.<!-- notionvc: 210ee4f2-90af-4cdf-8dbc-96d1fa8f67c7 --></p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,2,3,3,5,7]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 2, 3, 3, 5, 7]</code>.</li> <li>In the second operation, the next 3 elements are removed, resulting in the array <code>[3, 5, 7]</code>, which has distinct elements.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,5,6,4,4]</span></p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 4]</code>.</li> <li>In the second operation, all remaining elements are removed, resulting in an empty array.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [6,7,8,9]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>The array already contains distinct elements. Therefore, the answer is 0.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 100</code></li> <li><code>1 &lt;= nums[i] &lt;= 100</code></li> </ul>
Array; Hash Table
Rust
use std::collections::HashSet; impl Solution { pub fn minimum_operations(nums: Vec<i32>) -> i32 { let mut s = HashSet::new(); for i in (0..nums.len()).rev() { if !s.insert(nums[i]) { return (i / 3) as i32 + 1; } } 0 } }
3,396
Minimum Number of Operations to Make Elements in Array Distinct
Easy
<p>You are given an integer array <code>nums</code>. You need to ensure that the elements in the array are <strong>distinct</strong>. To achieve this, you can perform the following operation any number of times:</p> <ul> <li>Remove 3 elements from the beginning of the array. If the array has fewer than 3 elements, remove all remaining elements.</li> </ul> <p><strong>Note</strong> that an empty array is considered to have distinct elements. Return the <strong>minimum</strong> number of operations needed to make the elements in the array distinct.<!-- notionvc: 210ee4f2-90af-4cdf-8dbc-96d1fa8f67c7 --></p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,2,3,3,5,7]</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 2, 3, 3, 5, 7]</code>.</li> <li>In the second operation, the next 3 elements are removed, resulting in the array <code>[3, 5, 7]</code>, which has distinct elements.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,5,6,4,4]</span></p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <ul> <li>In the first operation, the first 3 elements are removed, resulting in the array <code>[4, 4]</code>.</li> <li>In the second operation, all remaining elements are removed, resulting in an empty array.</li> </ul> <p>Therefore, the answer is 2.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [6,7,8,9]</span></p> <p><strong>Output:</strong> <span class="example-io">0</span></p> <p><strong>Explanation:</strong></p> <p>The array already contains distinct elements. Therefore, the answer is 0.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 100</code></li> <li><code>1 &lt;= nums[i] &lt;= 100</code></li> </ul>
Array; Hash Table
TypeScript
function minimumOperations(nums: number[]): number { const s = new Set<number>(); for (let i = nums.length - 1; ~i; --i) { if (s.has(nums[i])) { return Math.ceil((i + 1) / 3); } s.add(nums[i]); } return 0; }
3,397
Maximum Number of Distinct Elements After Operations
Medium
<p>You are given an integer array <code>nums</code> and an integer <code>k</code>.</p> <p>You are allowed to perform the following <strong>operation</strong> on each element of the array <strong>at most</strong> <em>once</em>:</p> <ul> <li>Add an integer in the range <code>[-k, k]</code> to the element.</li> </ul> <p>Return the <strong>maximum</strong> possible number of <strong>distinct</strong> elements in <code>nums</code> after performing the <strong>operations</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,2,3,3,4], k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p><code>nums</code> changes to <code>[-1, 0, 1, 2, 3, 4]</code> after performing operations on the first four elements.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,4,4,4], k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>By adding -1 to <code>nums[0]</code> and 1 to <code>nums[1]</code>, <code>nums</code> changes to <code>[3, 5, 4, 4]</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= k &lt;= 10<sup>9</sup></code></li> </ul>
Greedy; Array; Sorting
C++
class Solution { public: int maxDistinctElements(vector<int>& nums, int k) { ranges::sort(nums); int ans = 0, pre = INT_MIN; for (int x : nums) { int cur = min(x + k, max(x - k, pre + 1)); if (cur > pre) { ++ans; pre = cur; } } return ans; } };
3,397
Maximum Number of Distinct Elements After Operations
Medium
<p>You are given an integer array <code>nums</code> and an integer <code>k</code>.</p> <p>You are allowed to perform the following <strong>operation</strong> on each element of the array <strong>at most</strong> <em>once</em>:</p> <ul> <li>Add an integer in the range <code>[-k, k]</code> to the element.</li> </ul> <p>Return the <strong>maximum</strong> possible number of <strong>distinct</strong> elements in <code>nums</code> after performing the <strong>operations</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,2,3,3,4], k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p><code>nums</code> changes to <code>[-1, 0, 1, 2, 3, 4]</code> after performing operations on the first four elements.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,4,4,4], k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>By adding -1 to <code>nums[0]</code> and 1 to <code>nums[1]</code>, <code>nums</code> changes to <code>[3, 5, 4, 4]</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= k &lt;= 10<sup>9</sup></code></li> </ul>
Greedy; Array; Sorting
Go
func maxDistinctElements(nums []int, k int) (ans int) { sort.Ints(nums) pre := math.MinInt32 for _, x := range nums { cur := min(x+k, max(x-k, pre+1)) if cur > pre { ans++ pre = cur } } return }
3,397
Maximum Number of Distinct Elements After Operations
Medium
<p>You are given an integer array <code>nums</code> and an integer <code>k</code>.</p> <p>You are allowed to perform the following <strong>operation</strong> on each element of the array <strong>at most</strong> <em>once</em>:</p> <ul> <li>Add an integer in the range <code>[-k, k]</code> to the element.</li> </ul> <p>Return the <strong>maximum</strong> possible number of <strong>distinct</strong> elements in <code>nums</code> after performing the <strong>operations</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,2,3,3,4], k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p><code>nums</code> changes to <code>[-1, 0, 1, 2, 3, 4]</code> after performing operations on the first four elements.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,4,4,4], k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>By adding -1 to <code>nums[0]</code> and 1 to <code>nums[1]</code>, <code>nums</code> changes to <code>[3, 5, 4, 4]</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= k &lt;= 10<sup>9</sup></code></li> </ul>
Greedy; Array; Sorting
Java
class Solution { public int maxDistinctElements(int[] nums, int k) { Arrays.sort(nums); int n = nums.length; int ans = 0, pre = Integer.MIN_VALUE; for (int x : nums) { int cur = Math.min(x + k, Math.max(x - k, pre + 1)); if (cur > pre) { ++ans; pre = cur; } } return ans; } }
3,397
Maximum Number of Distinct Elements After Operations
Medium
<p>You are given an integer array <code>nums</code> and an integer <code>k</code>.</p> <p>You are allowed to perform the following <strong>operation</strong> on each element of the array <strong>at most</strong> <em>once</em>:</p> <ul> <li>Add an integer in the range <code>[-k, k]</code> to the element.</li> </ul> <p>Return the <strong>maximum</strong> possible number of <strong>distinct</strong> elements in <code>nums</code> after performing the <strong>operations</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,2,3,3,4], k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p><code>nums</code> changes to <code>[-1, 0, 1, 2, 3, 4]</code> after performing operations on the first four elements.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,4,4,4], k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>By adding -1 to <code>nums[0]</code> and 1 to <code>nums[1]</code>, <code>nums</code> changes to <code>[3, 5, 4, 4]</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= k &lt;= 10<sup>9</sup></code></li> </ul>
Greedy; Array; Sorting
Python
class Solution: def maxDistinctElements(self, nums: List[int], k: int) -> int: nums.sort() ans = 0 pre = -inf for x in nums: cur = min(x + k, max(x - k, pre + 1)) if cur > pre: ans += 1 pre = cur return ans
3,397
Maximum Number of Distinct Elements After Operations
Medium
<p>You are given an integer array <code>nums</code> and an integer <code>k</code>.</p> <p>You are allowed to perform the following <strong>operation</strong> on each element of the array <strong>at most</strong> <em>once</em>:</p> <ul> <li>Add an integer in the range <code>[-k, k]</code> to the element.</li> </ul> <p>Return the <strong>maximum</strong> possible number of <strong>distinct</strong> elements in <code>nums</code> after performing the <strong>operations</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,2,3,3,4], k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p><code>nums</code> changes to <code>[-1, 0, 1, 2, 3, 4]</code> after performing operations on the first four elements.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [4,4,4,4], k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>By adding -1 to <code>nums[0]</code> and 1 to <code>nums[1]</code>, <code>nums</code> changes to <code>[3, 5, 4, 4]</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= k &lt;= 10<sup>9</sup></code></li> </ul>
Greedy; Array; Sorting
TypeScript
function maxDistinctElements(nums: number[], k: number): number { nums.sort((a, b) => a - b); let [ans, pre] = [0, -Infinity]; for (const x of nums) { const cur = Math.min(x + k, Math.max(x - k, pre + 1)); if (cur > pre) { ++ans; pre = cur; } } return ans; }
3,398
Smallest Substring With Identical Characters I
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 1000</code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
Array; Binary Search; Enumeration
C++
class Solution { public: int minLength(string s, int numOps) { int n = s.size(); auto check = [&](int m) { int cnt = 0; if (m == 1) { string t = "01"; for (int i = 0; i < n; ++i) { if (s[i] == t[i & 1]) { ++cnt; } } cnt = min(cnt, n - cnt); } else { int k = 0; for (int i = 0; i < n; ++i) { ++k; if (i == n - 1 || s[i] != s[i + 1]) { cnt += k / (m + 1); k = 0; } } } return cnt <= numOps; }; int l = 1, r = n; while (l < r) { int mid = (l + r) >> 1; if (check(mid)) { r = mid; } else { l = mid + 1; } } return l; } };
3,398
Smallest Substring With Identical Characters I
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 1000</code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
Array; Binary Search; Enumeration
Go
func minLength(s string, numOps int) int { check := func(m int) bool { m++ cnt := 0 if m == 1 { t := "01" for i := range s { if s[i] == t[i&1] { cnt++ } } cnt = min(cnt, len(s)-cnt) } else { k := 0 for i := range s { k++ if i == len(s)-1 || s[i] != s[i+1] { cnt += k / (m + 1) k = 0 } } } return cnt <= numOps } return 1 + sort.Search(len(s), func(m int) bool { return check(m) }) }
3,398
Smallest Substring With Identical Characters I
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 1000</code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
Array; Binary Search; Enumeration
Java
class Solution { private char[] s; private int numOps; public int minLength(String s, int numOps) { this.numOps = numOps; this.s = s.toCharArray(); int l = 1, r = s.length(); while (l < r) { int mid = (l + r) >> 1; if (check(mid)) { r = mid; } else { l = mid + 1; } } return l; } private boolean check(int m) { int cnt = 0; if (m == 1) { char[] t = {'0', '1'}; for (int i = 0; i < s.length; ++i) { if (s[i] == t[i & 1]) { ++cnt; } } cnt = Math.min(cnt, s.length - cnt); } else { int k = 0; for (int i = 0; i < s.length; ++i) { ++k; if (i == s.length - 1 || s[i] != s[i + 1]) { cnt += k / (m + 1); k = 0; } } } return cnt <= numOps; } }
3,398
Smallest Substring With Identical Characters I
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 1000</code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
Array; Binary Search; Enumeration
Python
class Solution: def minLength(self, s: str, numOps: int) -> int: def check(m: int) -> bool: cnt = 0 if m == 1: t = "01" cnt = sum(c == t[i & 1] for i, c in enumerate(s)) cnt = min(cnt, n - cnt) else: k = 0 for i, c in enumerate(s): k += 1 if i == len(s) - 1 or c != s[i + 1]: cnt += k // (m + 1) k = 0 return cnt <= numOps n = len(s) return bisect_left(range(n), True, lo=1, key=check)
3,398
Smallest Substring With Identical Characters I
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 1000</code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
Array; Binary Search; Enumeration
TypeScript
function minLength(s: string, numOps: number): number { const n = s.length; const check = (m: number): boolean => { let cnt = 0; if (m === 1) { const t = '01'; for (let i = 0; i < n; ++i) { if (s[i] === t[i & 1]) { ++cnt; } } cnt = Math.min(cnt, n - cnt); } else { let k = 0; for (let i = 0; i < n; ++i) { ++k; if (i === n - 1 || s[i] !== s[i + 1]) { cnt += Math.floor(k / (m + 1)); k = 0; } } } return cnt <= numOps; }; let [l, r] = [1, n]; while (l < r) { const mid = (l + r) >> 1; if (check(mid)) { r = mid; } else { l = mid + 1; } } return l; }
3,399
Smallest Substring With Identical Characters II
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 10<sup>5</sup></code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
String; Binary Search
C++
class Solution { public: int minLength(string s, int numOps) { int n = s.size(); auto check = [&](int m) { int cnt = 0; if (m == 1) { string t = "01"; for (int i = 0; i < n; ++i) { if (s[i] == t[i & 1]) { ++cnt; } } cnt = min(cnt, n - cnt); } else { int k = 0; for (int i = 0; i < n; ++i) { ++k; if (i == n - 1 || s[i] != s[i + 1]) { cnt += k / (m + 1); k = 0; } } } return cnt <= numOps; }; int l = 1, r = n; while (l < r) { int mid = (l + r) >> 1; if (check(mid)) { r = mid; } else { l = mid + 1; } } return l; } };
3,399
Smallest Substring With Identical Characters II
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 10<sup>5</sup></code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
String; Binary Search
Go
func minLength(s string, numOps int) int { check := func(m int) bool { m++ cnt := 0 if m == 1 { t := "01" for i := range s { if s[i] == t[i&1] { cnt++ } } cnt = min(cnt, len(s)-cnt) } else { k := 0 for i := range s { k++ if i == len(s)-1 || s[i] != s[i+1] { cnt += k / (m + 1) k = 0 } } } return cnt <= numOps } return 1 + sort.Search(len(s), func(m int) bool { return check(m) }) }
3,399
Smallest Substring With Identical Characters II
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 10<sup>5</sup></code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
String; Binary Search
Java
class Solution { private char[] s; private int numOps; public int minLength(String s, int numOps) { this.numOps = numOps; this.s = s.toCharArray(); int l = 1, r = s.length(); while (l < r) { int mid = (l + r) >> 1; if (check(mid)) { r = mid; } else { l = mid + 1; } } return l; } private boolean check(int m) { int cnt = 0; if (m == 1) { char[] t = {'0', '1'}; for (int i = 0; i < s.length; ++i) { if (s[i] == t[i & 1]) { ++cnt; } } cnt = Math.min(cnt, s.length - cnt); } else { int k = 0; for (int i = 0; i < s.length; ++i) { ++k; if (i == s.length - 1 || s[i] != s[i + 1]) { cnt += k / (m + 1); k = 0; } } } return cnt <= numOps; } }
3,399
Smallest Substring With Identical Characters II
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 10<sup>5</sup></code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
String; Binary Search
Python
class Solution: def minLength(self, s: str, numOps: int) -> int: def check(m: int) -> bool: cnt = 0 if m == 1: t = "01" cnt = sum(c == t[i & 1] for i, c in enumerate(s)) cnt = min(cnt, n - cnt) else: k = 0 for i, c in enumerate(s): k += 1 if i == len(s) - 1 or c != s[i + 1]: cnt += k // (m + 1) k = 0 return cnt <= numOps n = len(s) return bisect_left(range(n), True, lo=1, key=check)
3,399
Smallest Substring With Identical Characters II
Hard
<p>You are given a binary string <code>s</code> of length <code>n</code> and an integer <code>numOps</code>.</p> <p>You are allowed to perform the following operation on <code>s</code> <strong>at most</strong> <code>numOps</code> times:</p> <ul> <li>Select any index <code>i</code> (where <code>0 &lt;= i &lt; n</code>) and <strong>flip</strong> <code>s[i]</code>. If <code>s[i] == &#39;1&#39;</code>, change <code>s[i]</code> to <code>&#39;0&#39;</code> and vice versa.</li> </ul> <p>You need to <strong>minimize</strong> the length of the <strong>longest</strong> <span data-keyword="substring-nonempty">substring</span> of <code>s</code> such that all the characters in the substring are <strong>identical</strong>.</p> <p>Return the <strong>minimum</strong> length after the operations.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;000001&quot;, numOps = 1</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;001001&quot;</code>. The longest substrings with identical characters are <code>s[0..1]</code> and <code>s[3..4]</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0000&quot;, numOps = 2</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>By changing <code>s[0]</code> and <code>s[2]</code> to <code>&#39;1&#39;</code>, <code>s</code> becomes <code>&quot;1010&quot;</code>.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;0101&quot;, numOps = 0</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n == s.length &lt;= 10<sup>5</sup></code></li> <li><code>s</code> consists only of <code>&#39;0&#39;</code> and <code>&#39;1&#39;</code>.</li> <li><code>0 &lt;= numOps &lt;= n</code></li> </ul>
String; Binary Search
TypeScript
function minLength(s: string, numOps: number): number { const n = s.length; const check = (m: number): boolean => { let cnt = 0; if (m === 1) { const t = '01'; for (let i = 0; i < n; ++i) { if (s[i] === t[i & 1]) { ++cnt; } } cnt = Math.min(cnt, n - cnt); } else { let k = 0; for (let i = 0; i < n; ++i) { ++k; if (i === n - 1 || s[i] !== s[i + 1]) { cnt += Math.floor(k / (m + 1)); k = 0; } } } return cnt <= numOps; }; let [l, r] = [1, n]; while (l < r) { const mid = (l + r) >> 1; if (check(mid)) { r = mid; } else { l = mid + 1; } } return l; }
3,400
Maximum Number of Matching Indices After Right Shifts
Medium
<p>You are given two integer arrays, <code>nums1</code> and <code>nums2</code>, of the same length.</p> <p>An index <code>i</code> is considered <strong>matching</strong> if <code>nums1[i] == nums2[i]</code>.</p> <p>Return the <strong>maximum</strong> number of <strong>matching</strong> indices after performing any number of <strong>right shifts</strong> on <code>nums1</code>.</p> <p>A <strong>right shift</strong> is defined as shifting the element at index <code>i</code> to index <code>(i + 1) % n</code>, for all indices.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [3,1,2,3,1,2], nums2 = [1,2,3,1,2,3]</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 2 times, it becomes <code>[1, 2, 3, 1, 2, 3]</code>. Every index matches, so the output is 6.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [1,4,2,5,3,1], nums2 = [2,3,1,2,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 3 times, it becomes <code>[5, 3, 1, 1, 4, 2]</code>. Indices 1, 2, and 4 match, so the output is 3.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>nums1.length == nums2.length</code></li> <li><code>1 &lt;= nums1.length, nums2.length &lt;= 3000</code></li> <li><code>1 &lt;= nums1[i], nums2[i] &lt;= 10<sup>9</sup></code></li> </ul>
Array; Two Pointers; Simulation
C++
class Solution { public: int maximumMatchingIndices(vector<int>& nums1, vector<int>& nums2) { int n = nums1.size(); int ans = 0; for (int k = 0; k < n; ++k) { int t = 0; for (int i = 0; i < n; ++i) { if (nums1[(i + k) % n] == nums2[i]) { ++t; } } ans = max(ans, t); } return ans; } };
3,400
Maximum Number of Matching Indices After Right Shifts
Medium
<p>You are given two integer arrays, <code>nums1</code> and <code>nums2</code>, of the same length.</p> <p>An index <code>i</code> is considered <strong>matching</strong> if <code>nums1[i] == nums2[i]</code>.</p> <p>Return the <strong>maximum</strong> number of <strong>matching</strong> indices after performing any number of <strong>right shifts</strong> on <code>nums1</code>.</p> <p>A <strong>right shift</strong> is defined as shifting the element at index <code>i</code> to index <code>(i + 1) % n</code>, for all indices.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [3,1,2,3,1,2], nums2 = [1,2,3,1,2,3]</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 2 times, it becomes <code>[1, 2, 3, 1, 2, 3]</code>. Every index matches, so the output is 6.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [1,4,2,5,3,1], nums2 = [2,3,1,2,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 3 times, it becomes <code>[5, 3, 1, 1, 4, 2]</code>. Indices 1, 2, and 4 match, so the output is 3.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>nums1.length == nums2.length</code></li> <li><code>1 &lt;= nums1.length, nums2.length &lt;= 3000</code></li> <li><code>1 &lt;= nums1[i], nums2[i] &lt;= 10<sup>9</sup></code></li> </ul>
Array; Two Pointers; Simulation
Go
func maximumMatchingIndices(nums1 []int, nums2 []int) (ans int) { n := len(nums1) for k := range nums1 { t := 0 for i, x := range nums2 { if nums1[(i+k)%n] == x { t++ } } ans = max(ans, t) } return }
3,400
Maximum Number of Matching Indices After Right Shifts
Medium
<p>You are given two integer arrays, <code>nums1</code> and <code>nums2</code>, of the same length.</p> <p>An index <code>i</code> is considered <strong>matching</strong> if <code>nums1[i] == nums2[i]</code>.</p> <p>Return the <strong>maximum</strong> number of <strong>matching</strong> indices after performing any number of <strong>right shifts</strong> on <code>nums1</code>.</p> <p>A <strong>right shift</strong> is defined as shifting the element at index <code>i</code> to index <code>(i + 1) % n</code>, for all indices.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [3,1,2,3,1,2], nums2 = [1,2,3,1,2,3]</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 2 times, it becomes <code>[1, 2, 3, 1, 2, 3]</code>. Every index matches, so the output is 6.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [1,4,2,5,3,1], nums2 = [2,3,1,2,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 3 times, it becomes <code>[5, 3, 1, 1, 4, 2]</code>. Indices 1, 2, and 4 match, so the output is 3.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>nums1.length == nums2.length</code></li> <li><code>1 &lt;= nums1.length, nums2.length &lt;= 3000</code></li> <li><code>1 &lt;= nums1[i], nums2[i] &lt;= 10<sup>9</sup></code></li> </ul>
Array; Two Pointers; Simulation
Java
class Solution { public int maximumMatchingIndices(int[] nums1, int[] nums2) { int n = nums1.length; int ans = 0; for (int k = 0; k < n; ++k) { int t = 0; for (int i = 0; i < n; ++i) { if (nums1[(i + k) % n] == nums2[i]) { ++t; } } ans = Math.max(ans, t); } return ans; } }
3,400
Maximum Number of Matching Indices After Right Shifts
Medium
<p>You are given two integer arrays, <code>nums1</code> and <code>nums2</code>, of the same length.</p> <p>An index <code>i</code> is considered <strong>matching</strong> if <code>nums1[i] == nums2[i]</code>.</p> <p>Return the <strong>maximum</strong> number of <strong>matching</strong> indices after performing any number of <strong>right shifts</strong> on <code>nums1</code>.</p> <p>A <strong>right shift</strong> is defined as shifting the element at index <code>i</code> to index <code>(i + 1) % n</code>, for all indices.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [3,1,2,3,1,2], nums2 = [1,2,3,1,2,3]</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 2 times, it becomes <code>[1, 2, 3, 1, 2, 3]</code>. Every index matches, so the output is 6.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [1,4,2,5,3,1], nums2 = [2,3,1,2,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 3 times, it becomes <code>[5, 3, 1, 1, 4, 2]</code>. Indices 1, 2, and 4 match, so the output is 3.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>nums1.length == nums2.length</code></li> <li><code>1 &lt;= nums1.length, nums2.length &lt;= 3000</code></li> <li><code>1 &lt;= nums1[i], nums2[i] &lt;= 10<sup>9</sup></code></li> </ul>
Array; Two Pointers; Simulation
Python
class Solution: def maximumMatchingIndices(self, nums1: List[int], nums2: List[int]) -> int: n = len(nums1) ans = 0 for k in range(n): t = sum(nums1[(i + k) % n] == x for i, x in enumerate(nums2)) ans = max(ans, t) return ans
3,400
Maximum Number of Matching Indices After Right Shifts
Medium
<p>You are given two integer arrays, <code>nums1</code> and <code>nums2</code>, of the same length.</p> <p>An index <code>i</code> is considered <strong>matching</strong> if <code>nums1[i] == nums2[i]</code>.</p> <p>Return the <strong>maximum</strong> number of <strong>matching</strong> indices after performing any number of <strong>right shifts</strong> on <code>nums1</code>.</p> <p>A <strong>right shift</strong> is defined as shifting the element at index <code>i</code> to index <code>(i + 1) % n</code>, for all indices.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [3,1,2,3,1,2], nums2 = [1,2,3,1,2,3]</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 2 times, it becomes <code>[1, 2, 3, 1, 2, 3]</code>. Every index matches, so the output is 6.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums1 = [1,4,2,5,3,1], nums2 = [2,3,1,2,4,6]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>If we right shift <code>nums1</code> 3 times, it becomes <code>[5, 3, 1, 1, 4, 2]</code>. Indices 1, 2, and 4 match, so the output is 3.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>nums1.length == nums2.length</code></li> <li><code>1 &lt;= nums1.length, nums2.length &lt;= 3000</code></li> <li><code>1 &lt;= nums1[i], nums2[i] &lt;= 10<sup>9</sup></code></li> </ul>
Array; Two Pointers; Simulation
TypeScript
function maximumMatchingIndices(nums1: number[], nums2: number[]): number { const n = nums1.length; let ans: number = 0; for (let k = 0; k < n; ++k) { let t: number = 0; for (let i = 0; i < n; ++i) { if (nums1[(i + k) % n] === nums2[i]) { ++t; } } ans = Math.max(ans, t); } return ans; }
3,402
Minimum Operations to Make Columns Strictly Increasing
Easy
<p>You are given a <code>m x n</code> matrix <code>grid</code> consisting of <b>non-negative</b> integers.</p> <p>In one operation, you can increment the value of any <code>grid[i][j]</code> by 1.</p> <p>Return the <strong>minimum</strong> number of operations needed to make all columns of <code>grid</code> <strong>strictly increasing</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2],[1,3],[3,4],[0,1]]</span></p> <p><strong>Output:</strong> <span class="example-io">15</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 3 operations on <code>grid[1][0]</code>, 2 operations on <code>grid[2][0]</code>, and 6 operations on <code>grid[3][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 4 operations on <code>grid[3][1]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/firstexample.png" style="width: 200px; height: 347px;" /></div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2,1],[2,1,0],[1,2,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">12</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][0]</code>, and 4 operations on <code>grid[2][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][1]</code>, and 2 operations on <code>grid[2][1]</code>.</li> <li>To make the <code>2<sup>nd</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][2]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/secondexample.png" style="width: 300px; height: 257px;" /></div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 50</code></li> <li><code>0 &lt;= grid[i][j] &lt; 2500</code></li> </ul> <p>&nbsp;</p> <div class="spoiler"> <div> <pre> &nbsp;</pre> </div> </div>
Greedy; Array; Matrix
C++
class Solution { public: int minimumOperations(vector<vector<int>>& grid) { int m = grid.size(), n = grid[0].size(); int ans = 0; for (int j = 0; j < n; ++j) { int pre = -1; for (int i = 0; i < m; ++i) { int cur = grid[i][j]; if (pre < cur) { pre = cur; } else { ++pre; ans += pre - cur; } } } return ans; } };
3,402
Minimum Operations to Make Columns Strictly Increasing
Easy
<p>You are given a <code>m x n</code> matrix <code>grid</code> consisting of <b>non-negative</b> integers.</p> <p>In one operation, you can increment the value of any <code>grid[i][j]</code> by 1.</p> <p>Return the <strong>minimum</strong> number of operations needed to make all columns of <code>grid</code> <strong>strictly increasing</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2],[1,3],[3,4],[0,1]]</span></p> <p><strong>Output:</strong> <span class="example-io">15</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 3 operations on <code>grid[1][0]</code>, 2 operations on <code>grid[2][0]</code>, and 6 operations on <code>grid[3][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 4 operations on <code>grid[3][1]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/firstexample.png" style="width: 200px; height: 347px;" /></div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2,1],[2,1,0],[1,2,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">12</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][0]</code>, and 4 operations on <code>grid[2][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][1]</code>, and 2 operations on <code>grid[2][1]</code>.</li> <li>To make the <code>2<sup>nd</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][2]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/secondexample.png" style="width: 300px; height: 257px;" /></div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 50</code></li> <li><code>0 &lt;= grid[i][j] &lt; 2500</code></li> </ul> <p>&nbsp;</p> <div class="spoiler"> <div> <pre> &nbsp;</pre> </div> </div>
Greedy; Array; Matrix
Go
func minimumOperations(grid [][]int) (ans int) { m, n := len(grid), len(grid[0]) for j := 0; j < n; j++ { pre := -1 for i := 0; i < m; i++ { cur := grid[i][j] if pre < cur { pre = cur } else { pre++ ans += pre - cur } } } return }
3,402
Minimum Operations to Make Columns Strictly Increasing
Easy
<p>You are given a <code>m x n</code> matrix <code>grid</code> consisting of <b>non-negative</b> integers.</p> <p>In one operation, you can increment the value of any <code>grid[i][j]</code> by 1.</p> <p>Return the <strong>minimum</strong> number of operations needed to make all columns of <code>grid</code> <strong>strictly increasing</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2],[1,3],[3,4],[0,1]]</span></p> <p><strong>Output:</strong> <span class="example-io">15</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 3 operations on <code>grid[1][0]</code>, 2 operations on <code>grid[2][0]</code>, and 6 operations on <code>grid[3][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 4 operations on <code>grid[3][1]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/firstexample.png" style="width: 200px; height: 347px;" /></div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2,1],[2,1,0],[1,2,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">12</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][0]</code>, and 4 operations on <code>grid[2][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][1]</code>, and 2 operations on <code>grid[2][1]</code>.</li> <li>To make the <code>2<sup>nd</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][2]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/secondexample.png" style="width: 300px; height: 257px;" /></div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 50</code></li> <li><code>0 &lt;= grid[i][j] &lt; 2500</code></li> </ul> <p>&nbsp;</p> <div class="spoiler"> <div> <pre> &nbsp;</pre> </div> </div>
Greedy; Array; Matrix
Java
class Solution { public int minimumOperations(int[][] grid) { int m = grid.length, n = grid[0].length; int ans = 0; for (int j = 0; j < n; ++j) { int pre = -1; for (int i = 0; i < m; ++i) { int cur = grid[i][j]; if (pre < cur) { pre = cur; } else { ++pre; ans += pre - cur; } } } return ans; } }
3,402
Minimum Operations to Make Columns Strictly Increasing
Easy
<p>You are given a <code>m x n</code> matrix <code>grid</code> consisting of <b>non-negative</b> integers.</p> <p>In one operation, you can increment the value of any <code>grid[i][j]</code> by 1.</p> <p>Return the <strong>minimum</strong> number of operations needed to make all columns of <code>grid</code> <strong>strictly increasing</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2],[1,3],[3,4],[0,1]]</span></p> <p><strong>Output:</strong> <span class="example-io">15</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 3 operations on <code>grid[1][0]</code>, 2 operations on <code>grid[2][0]</code>, and 6 operations on <code>grid[3][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 4 operations on <code>grid[3][1]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/firstexample.png" style="width: 200px; height: 347px;" /></div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2,1],[2,1,0],[1,2,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">12</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][0]</code>, and 4 operations on <code>grid[2][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][1]</code>, and 2 operations on <code>grid[2][1]</code>.</li> <li>To make the <code>2<sup>nd</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][2]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/secondexample.png" style="width: 300px; height: 257px;" /></div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 50</code></li> <li><code>0 &lt;= grid[i][j] &lt; 2500</code></li> </ul> <p>&nbsp;</p> <div class="spoiler"> <div> <pre> &nbsp;</pre> </div> </div>
Greedy; Array; Matrix
Python
class Solution: def minimumOperations(self, grid: List[List[int]]) -> int: ans = 0 for col in zip(*grid): pre = -1 for cur in col: if pre < cur: pre = cur else: pre += 1 ans += pre - cur return ans
3,402
Minimum Operations to Make Columns Strictly Increasing
Easy
<p>You are given a <code>m x n</code> matrix <code>grid</code> consisting of <b>non-negative</b> integers.</p> <p>In one operation, you can increment the value of any <code>grid[i][j]</code> by 1.</p> <p>Return the <strong>minimum</strong> number of operations needed to make all columns of <code>grid</code> <strong>strictly increasing</strong>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2],[1,3],[3,4],[0,1]]</span></p> <p><strong>Output:</strong> <span class="example-io">15</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 3 operations on <code>grid[1][0]</code>, 2 operations on <code>grid[2][0]</code>, and 6 operations on <code>grid[3][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 4 operations on <code>grid[3][1]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/firstexample.png" style="width: 200px; height: 347px;" /></div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">grid = [[3,2,1],[2,1,0],[1,2,3]]</span></p> <p><strong>Output:</strong> <span class="example-io">12</span></p> <p><strong>Explanation:</strong></p> <ul> <li>To make the <code>0<sup>th</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][0]</code>, and 4 operations on <code>grid[2][0]</code>.</li> <li>To make the <code>1<sup>st</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][1]</code>, and 2 operations on <code>grid[2][1]</code>.</li> <li>To make the <code>2<sup>nd</sup></code> column strictly increasing, we can apply 2 operations on <code>grid[1][2]</code>.</li> </ul> <img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/3400-3499/3402.Minimum%20Operations%20to%20Make%20Columns%20Strictly%20Increasing/images/secondexample.png" style="width: 300px; height: 257px;" /></div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == grid.length</code></li> <li><code>n == grid[i].length</code></li> <li><code>1 &lt;= m, n &lt;= 50</code></li> <li><code>0 &lt;= grid[i][j] &lt; 2500</code></li> </ul> <p>&nbsp;</p> <div class="spoiler"> <div> <pre> &nbsp;</pre> </div> </div>
Greedy; Array; Matrix
TypeScript
function minimumOperations(grid: number[][]): number { const [m, n] = [grid.length, grid[0].length]; let ans: number = 0; for (let j = 0; j < n; ++j) { let pre: number = -1; for (let i = 0; i < m; ++i) { const cur = grid[i][j]; if (pre < cur) { pre = cur; } else { ++pre; ans += pre - cur; } } } return ans; }
3,403
Find the Lexicographically Largest String From the Box I
Medium
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <span data-keyword="lexicographically-smaller-string">lexicographically largest</span> string from the box after all the rounds are finished.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 5&nbsp;* 10<sup>3</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String; Enumeration
C++
class Solution { public: string answerString(string word, int numFriends) { if (numFriends == 1) { return word; } int n = word.length(); string ans = ""; for (int i = 0; i < n; ++i) { string t = word.substr(i, min(n - i, n - (numFriends - 1))); if (ans < t) { ans = t; } } return ans; } };
3,403
Find the Lexicographically Largest String From the Box I
Medium
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <span data-keyword="lexicographically-smaller-string">lexicographically largest</span> string from the box after all the rounds are finished.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 5&nbsp;* 10<sup>3</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String; Enumeration
Go
func answerString(word string, numFriends int) (ans string) { if numFriends == 1 { return word } n := len(word) for i := 0; i < n; i++ { t := word[i:min(n, i+n-(numFriends-1))] ans = max(ans, t) } return }
3,403
Find the Lexicographically Largest String From the Box I
Medium
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <span data-keyword="lexicographically-smaller-string">lexicographically largest</span> string from the box after all the rounds are finished.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 5&nbsp;* 10<sup>3</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String; Enumeration
Java
class Solution { public String answerString(String word, int numFriends) { if (numFriends == 1) { return word; } int n = word.length(); String ans = ""; for (int i = 0; i < n; ++i) { String t = word.substring(i, Math.min(n, i + n - (numFriends - 1))); if (ans.compareTo(t) < 0) { ans = t; } } return ans; } }
3,403
Find the Lexicographically Largest String From the Box I
Medium
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <span data-keyword="lexicographically-smaller-string">lexicographically largest</span> string from the box after all the rounds are finished.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 5&nbsp;* 10<sup>3</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String; Enumeration
Python
class Solution: def answerString(self, word: str, numFriends: int) -> str: if numFriends == 1: return word n = len(word) return max(word[i : i + n - (numFriends - 1)] for i in range(n))
3,403
Find the Lexicographically Largest String From the Box I
Medium
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <span data-keyword="lexicographically-smaller-string">lexicographically largest</span> string from the box after all the rounds are finished.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 5&nbsp;* 10<sup>3</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String; Enumeration
TypeScript
function answerString(word: string, numFriends: number): string { if (numFriends === 1) { return word; } const n = word.length; let ans = ''; for (let i = 0; i < n; i++) { const t = word.slice(i, Math.min(n, i + n - (numFriends - 1))); ans = t > ans ? t : ans; } return ans; }
3,404
Count Special Subsequences
Medium
<p>You are given an array <code>nums</code> consisting of positive integers.</p> <p>A <strong>special subsequence</strong> is defined as a <span data-keyword="subsequence-array">subsequence</span> of length 4, represented by indices <code>(p, q, r, s)</code>, where <code>p &lt; q &lt; r &lt; s</code>. This subsequence <strong>must</strong> satisfy the following conditions:</p> <ul> <li><code>nums[p] * nums[r] == nums[q] * nums[s]</code></li> <li>There must be <em>at least</em> <strong>one</strong> element between each pair of indices. In other words, <code>q - p &gt; 1</code>, <code>r - q &gt; 1</code> and <code>s - r &gt; 1</code>.</li> </ul> <p>Return the <em>number</em> of different <strong>special</strong> <strong>subsequences</strong> in <code>nums</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,3,6,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>There is one special subsequence in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(1, 3, 3, 1)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 1 * 3 = 3</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 1 = 3</code></li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [3,4,3,4,3,4,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>There are three special subsequences in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 3, 3)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 3 * 3 = 9</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 3 = 9</code></li> </ul> </li> <li><code>(p, q, r, s) = (1, 3, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(4, 4, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[1] * nums[5] = 4 * 4 = 16</code></li> <li><code>nums[q] * nums[s] = nums[3] * nums[7] = 4 * 4 = 16</code></li> </ul> </li> <li><code>(p, q, r, s) = (0, 2, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[5] = 3 * 4 = 12</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[7] = 3 * 4 = 12</code></li> </ul> </li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>7 &lt;= nums.length &lt;= 1000</code></li> <li><code>1 &lt;= nums[i] &lt;= 1000</code></li> </ul>
Array; Hash Table; Math; Enumeration
C++
class Solution { public: long long numberOfSubsequences(vector<int>& nums) { int n = nums.size(); unordered_map<int, int> cnt; for (int r = 4; r < n - 2; ++r) { int c = nums[r]; for (int s = r + 2; s < n; ++s) { int d = nums[s]; int g = gcd(c, d); cnt[((d / g) << 12) | (c / g)]++; } } long long ans = 0; for (int q = 2; q < n - 4; ++q) { int b = nums[q]; for (int p = 0; p < q - 1; ++p) { int a = nums[p]; int g = gcd(a, b); ans += cnt[((a / g) << 12) | (b / g)]; } int c = nums[q + 2]; for (int s = q + 4; s < n; ++s) { int d = nums[s]; int g = gcd(c, d); cnt[((d / g) << 12) | (c / g)]--; } } return ans; } };
3,404
Count Special Subsequences
Medium
<p>You are given an array <code>nums</code> consisting of positive integers.</p> <p>A <strong>special subsequence</strong> is defined as a <span data-keyword="subsequence-array">subsequence</span> of length 4, represented by indices <code>(p, q, r, s)</code>, where <code>p &lt; q &lt; r &lt; s</code>. This subsequence <strong>must</strong> satisfy the following conditions:</p> <ul> <li><code>nums[p] * nums[r] == nums[q] * nums[s]</code></li> <li>There must be <em>at least</em> <strong>one</strong> element between each pair of indices. In other words, <code>q - p &gt; 1</code>, <code>r - q &gt; 1</code> and <code>s - r &gt; 1</code>.</li> </ul> <p>Return the <em>number</em> of different <strong>special</strong> <strong>subsequences</strong> in <code>nums</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,3,6,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>There is one special subsequence in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(1, 3, 3, 1)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 1 * 3 = 3</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 1 = 3</code></li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [3,4,3,4,3,4,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>There are three special subsequences in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 3, 3)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 3 * 3 = 9</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 3 = 9</code></li> </ul> </li> <li><code>(p, q, r, s) = (1, 3, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(4, 4, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[1] * nums[5] = 4 * 4 = 16</code></li> <li><code>nums[q] * nums[s] = nums[3] * nums[7] = 4 * 4 = 16</code></li> </ul> </li> <li><code>(p, q, r, s) = (0, 2, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[5] = 3 * 4 = 12</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[7] = 3 * 4 = 12</code></li> </ul> </li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>7 &lt;= nums.length &lt;= 1000</code></li> <li><code>1 &lt;= nums[i] &lt;= 1000</code></li> </ul>
Array; Hash Table; Math; Enumeration
Go
func numberOfSubsequences(nums []int) (ans int64) { n := len(nums) cnt := make(map[int]int) gcd := func(a, b int) int { for b != 0 { a, b = b, a%b } return a } for r := 4; r < n-2; r++ { c := nums[r] for s := r + 2; s < n; s++ { d := nums[s] g := gcd(c, d) key := ((d / g) << 12) | (c / g) cnt[key]++ } } for q := 2; q < n-4; q++ { b := nums[q] for p := 0; p < q-1; p++ { a := nums[p] g := gcd(a, b) key := ((a / g) << 12) | (b / g) ans += int64(cnt[key]) } c := nums[q+2] for s := q + 4; s < n; s++ { d := nums[s] g := gcd(c, d) key := ((d / g) << 12) | (c / g) cnt[key]-- } } return }
3,404
Count Special Subsequences
Medium
<p>You are given an array <code>nums</code> consisting of positive integers.</p> <p>A <strong>special subsequence</strong> is defined as a <span data-keyword="subsequence-array">subsequence</span> of length 4, represented by indices <code>(p, q, r, s)</code>, where <code>p &lt; q &lt; r &lt; s</code>. This subsequence <strong>must</strong> satisfy the following conditions:</p> <ul> <li><code>nums[p] * nums[r] == nums[q] * nums[s]</code></li> <li>There must be <em>at least</em> <strong>one</strong> element between each pair of indices. In other words, <code>q - p &gt; 1</code>, <code>r - q &gt; 1</code> and <code>s - r &gt; 1</code>.</li> </ul> <p>Return the <em>number</em> of different <strong>special</strong> <strong>subsequences</strong> in <code>nums</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,3,6,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>There is one special subsequence in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(1, 3, 3, 1)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 1 * 3 = 3</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 1 = 3</code></li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [3,4,3,4,3,4,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>There are three special subsequences in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 3, 3)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 3 * 3 = 9</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 3 = 9</code></li> </ul> </li> <li><code>(p, q, r, s) = (1, 3, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(4, 4, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[1] * nums[5] = 4 * 4 = 16</code></li> <li><code>nums[q] * nums[s] = nums[3] * nums[7] = 4 * 4 = 16</code></li> </ul> </li> <li><code>(p, q, r, s) = (0, 2, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[5] = 3 * 4 = 12</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[7] = 3 * 4 = 12</code></li> </ul> </li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>7 &lt;= nums.length &lt;= 1000</code></li> <li><code>1 &lt;= nums[i] &lt;= 1000</code></li> </ul>
Array; Hash Table; Math; Enumeration
Java
class Solution { public long numberOfSubsequences(int[] nums) { int n = nums.length; Map<Integer, Integer> cnt = new HashMap<>(); for (int r = 4; r < n - 2; ++r) { int c = nums[r]; for (int s = r + 2; s < n; ++s) { int d = nums[s]; int g = gcd(c, d); cnt.merge(((d / g) << 12) | (c / g), 1, Integer::sum); } } long ans = 0; for (int q = 2; q < n - 4; ++q) { int b = nums[q]; for (int p = 0; p < q - 1; ++p) { int a = nums[p]; int g = gcd(a, b); ans += cnt.getOrDefault(((a / g) << 12) | (b / g), 0); } int c = nums[q + 2]; for (int s = q + 4; s < n; ++s) { int d = nums[s]; int g = gcd(c, d); cnt.merge(((d / g) << 12) | (c / g), -1, Integer::sum); } } return ans; } private int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); } }
3,404
Count Special Subsequences
Medium
<p>You are given an array <code>nums</code> consisting of positive integers.</p> <p>A <strong>special subsequence</strong> is defined as a <span data-keyword="subsequence-array">subsequence</span> of length 4, represented by indices <code>(p, q, r, s)</code>, where <code>p &lt; q &lt; r &lt; s</code>. This subsequence <strong>must</strong> satisfy the following conditions:</p> <ul> <li><code>nums[p] * nums[r] == nums[q] * nums[s]</code></li> <li>There must be <em>at least</em> <strong>one</strong> element between each pair of indices. In other words, <code>q - p &gt; 1</code>, <code>r - q &gt; 1</code> and <code>s - r &gt; 1</code>.</li> </ul> <p>Return the <em>number</em> of different <strong>special</strong> <strong>subsequences</strong> in <code>nums</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,3,6,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>There is one special subsequence in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(1, 3, 3, 1)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 1 * 3 = 3</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 1 = 3</code></li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [3,4,3,4,3,4,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>There are three special subsequences in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 3, 3)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 3 * 3 = 9</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 3 = 9</code></li> </ul> </li> <li><code>(p, q, r, s) = (1, 3, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(4, 4, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[1] * nums[5] = 4 * 4 = 16</code></li> <li><code>nums[q] * nums[s] = nums[3] * nums[7] = 4 * 4 = 16</code></li> </ul> </li> <li><code>(p, q, r, s) = (0, 2, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[5] = 3 * 4 = 12</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[7] = 3 * 4 = 12</code></li> </ul> </li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>7 &lt;= nums.length &lt;= 1000</code></li> <li><code>1 &lt;= nums[i] &lt;= 1000</code></li> </ul>
Array; Hash Table; Math; Enumeration
Python
class Solution: def numberOfSubsequences(self, nums: List[int]) -> int: n = len(nums) cnt = defaultdict(int) for r in range(4, n - 2): c = nums[r] for s in range(r + 2, n): d = nums[s] g = gcd(c, d) cnt[(d // g, c // g)] += 1 ans = 0 for q in range(2, n - 4): b = nums[q] for p in range(q - 1): a = nums[p] g = gcd(a, b) ans += cnt[(a // g, b // g)] c = nums[q + 2] for s in range(q + 4, n): d = nums[s] g = gcd(c, d) cnt[(d // g, c // g)] -= 1 return ans
3,404
Count Special Subsequences
Medium
<p>You are given an array <code>nums</code> consisting of positive integers.</p> <p>A <strong>special subsequence</strong> is defined as a <span data-keyword="subsequence-array">subsequence</span> of length 4, represented by indices <code>(p, q, r, s)</code>, where <code>p &lt; q &lt; r &lt; s</code>. This subsequence <strong>must</strong> satisfy the following conditions:</p> <ul> <li><code>nums[p] * nums[r] == nums[q] * nums[s]</code></li> <li>There must be <em>at least</em> <strong>one</strong> element between each pair of indices. In other words, <code>q - p &gt; 1</code>, <code>r - q &gt; 1</code> and <code>s - r &gt; 1</code>.</li> </ul> <p>Return the <em>number</em> of different <strong>special</strong> <strong>subsequences</strong> in <code>nums</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,4,3,6,1]</span></p> <p><strong>Output:</strong> <span class="example-io">1</span></p> <p><strong>Explanation:</strong></p> <p>There is one special subsequence in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(1, 3, 3, 1)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 1 * 3 = 3</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 1 = 3</code></li> </ul> </li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [3,4,3,4,3,4,3,4]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong></p> <p>There are three special subsequences in <code>nums</code>.</p> <ul> <li><code>(p, q, r, s) = (0, 2, 4, 6)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 3, 3)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[4] = 3 * 3 = 9</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[6] = 3 * 3 = 9</code></li> </ul> </li> <li><code>(p, q, r, s) = (1, 3, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(4, 4, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[1] * nums[5] = 4 * 4 = 16</code></li> <li><code>nums[q] * nums[s] = nums[3] * nums[7] = 4 * 4 = 16</code></li> </ul> </li> <li><code>(p, q, r, s) = (0, 2, 5, 7)</code>: <ul> <li>This corresponds to elements <code>(3, 3, 4, 4)</code>.</li> <li><code>nums[p] * nums[r] = nums[0] * nums[5] = 3 * 4 = 12</code></li> <li><code>nums[q] * nums[s] = nums[2] * nums[7] = 3 * 4 = 12</code></li> </ul> </li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>7 &lt;= nums.length &lt;= 1000</code></li> <li><code>1 &lt;= nums[i] &lt;= 1000</code></li> </ul>
Array; Hash Table; Math; Enumeration
TypeScript
function numberOfSubsequences(nums: number[]): number { const n = nums.length; const cnt = new Map<number, number>(); function gcd(a: number, b: number): number { while (b !== 0) { [a, b] = [b, a % b]; } return a; } for (let r = 4; r < n - 2; r++) { const c = nums[r]; for (let s = r + 2; s < n; s++) { const d = nums[s]; const g = gcd(c, d); const key = ((d / g) << 12) | (c / g); cnt.set(key, (cnt.get(key) || 0) + 1); } } let ans = 0; for (let q = 2; q < n - 4; q++) { const b = nums[q]; for (let p = 0; p < q - 1; p++) { const a = nums[p]; const g = gcd(a, b); const key = ((a / g) << 12) | (b / g); ans += cnt.get(key) || 0; } const c = nums[q + 2]; for (let s = q + 4; s < n; s++) { const d = nums[s]; const g = gcd(c, d); const key = ((d / g) << 12) | (c / g); cnt.set(key, (cnt.get(key) || 0) - 1); } } return ans; }
3,405
Count the Number of Arrays with K Matching Adjacent Elements
Hard
<p>You are given three integers <code>n</code>, <code>m</code>, <code>k</code>. A <strong>good array</strong> <code>arr</code> of size <code>n</code> is defined as follows:</p> <ul> <li>Each element in <code>arr</code> is in the <strong>inclusive</strong> range <code>[1, m]</code>.</li> <li><em>Exactly</em> <code>k</code> indices <code>i</code> (where <code>1 &lt;= i &lt; n</code>) satisfy the condition <code>arr[i - 1] == arr[i]</code>.</li> </ul> <p>Return the number of <strong>good arrays</strong> that can be formed.</p> <p>Since the answer may be very large, return it <strong>modulo </strong><code>10<sup>9 </sup>+ 7</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 3, m = 2, k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <ul> <li>There are 4 good arrays. They are <code>[1, 1, 2]</code>, <code>[1, 2, 2]</code>, <code>[2, 1, 1]</code> and <code>[2, 2, 1]</code>.</li> <li>Hence, the answer is 4.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, m = 2, k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 1, 1, 2]</code>, <code>[1, 1, 2, 2]</code>, <code>[1, 2, 2, 2]</code>, <code>[2, 1, 1, 1]</code>, <code>[2, 2, 1, 1]</code> and <code>[2, 2, 2, 1]</code>.</li> <li>Hence, the answer is 6.</li> </ul> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, m = 2, k = 0</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 2, 1, 2, 1]</code> and <code>[2, 1, 2, 1, 2]</code>. Hence, the answer is 2.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= m &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= k &lt;= n - 1</code></li> </ul>
Math; Combinatorics
C++
const int MX = 1e5 + 10; const int MOD = 1e9 + 7; long long f[MX]; long long g[MX]; long long qpow(long a, int k) { long res = 1; while (k != 0) { if ((k & 1) == 1) { res = res * a % MOD; } k >>= 1; a = a * a % MOD; } return res; } int init = []() { f[0] = g[0] = 1; for (int i = 1; i < MX; ++i) { f[i] = f[i - 1] * i % MOD; g[i] = qpow(f[i], MOD - 2); } return 0; }(); long long comb(int m, int n) { return f[m] * g[n] % MOD * g[m - n] % MOD; } class Solution { public: int countGoodArrays(int n, int m, int k) { return comb(n - 1, k) * m % MOD * qpow(m - 1, n - k - 1) % MOD; } };
3,405
Count the Number of Arrays with K Matching Adjacent Elements
Hard
<p>You are given three integers <code>n</code>, <code>m</code>, <code>k</code>. A <strong>good array</strong> <code>arr</code> of size <code>n</code> is defined as follows:</p> <ul> <li>Each element in <code>arr</code> is in the <strong>inclusive</strong> range <code>[1, m]</code>.</li> <li><em>Exactly</em> <code>k</code> indices <code>i</code> (where <code>1 &lt;= i &lt; n</code>) satisfy the condition <code>arr[i - 1] == arr[i]</code>.</li> </ul> <p>Return the number of <strong>good arrays</strong> that can be formed.</p> <p>Since the answer may be very large, return it <strong>modulo </strong><code>10<sup>9 </sup>+ 7</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 3, m = 2, k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <ul> <li>There are 4 good arrays. They are <code>[1, 1, 2]</code>, <code>[1, 2, 2]</code>, <code>[2, 1, 1]</code> and <code>[2, 2, 1]</code>.</li> <li>Hence, the answer is 4.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, m = 2, k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 1, 1, 2]</code>, <code>[1, 1, 2, 2]</code>, <code>[1, 2, 2, 2]</code>, <code>[2, 1, 1, 1]</code>, <code>[2, 2, 1, 1]</code> and <code>[2, 2, 2, 1]</code>.</li> <li>Hence, the answer is 6.</li> </ul> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, m = 2, k = 0</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 2, 1, 2, 1]</code> and <code>[2, 1, 2, 1, 2]</code>. Hence, the answer is 2.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= m &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= k &lt;= n - 1</code></li> </ul>
Math; Combinatorics
Go
const MX = 1e5 + 10 const MOD = 1e9 + 7 var f [MX]int64 var g [MX]int64 func qpow(a int64, k int) int64 { res := int64(1) for k != 0 { if k&1 == 1 { res = res * a % MOD } a = a * a % MOD k >>= 1 } return res } func init() { f[0], g[0] = 1, 1 for i := 1; i < MX; i++ { f[i] = f[i-1] * int64(i) % MOD g[i] = qpow(f[i], MOD-2) } } func comb(m, n int) int64 { return f[m] * g[n] % MOD * g[m-n] % MOD } func countGoodArrays(n int, m int, k int) int { ans := comb(n-1, k) * int64(m) % MOD * qpow(int64(m-1), n-k-1) % MOD return int(ans) }
3,405
Count the Number of Arrays with K Matching Adjacent Elements
Hard
<p>You are given three integers <code>n</code>, <code>m</code>, <code>k</code>. A <strong>good array</strong> <code>arr</code> of size <code>n</code> is defined as follows:</p> <ul> <li>Each element in <code>arr</code> is in the <strong>inclusive</strong> range <code>[1, m]</code>.</li> <li><em>Exactly</em> <code>k</code> indices <code>i</code> (where <code>1 &lt;= i &lt; n</code>) satisfy the condition <code>arr[i - 1] == arr[i]</code>.</li> </ul> <p>Return the number of <strong>good arrays</strong> that can be formed.</p> <p>Since the answer may be very large, return it <strong>modulo </strong><code>10<sup>9 </sup>+ 7</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 3, m = 2, k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <ul> <li>There are 4 good arrays. They are <code>[1, 1, 2]</code>, <code>[1, 2, 2]</code>, <code>[2, 1, 1]</code> and <code>[2, 2, 1]</code>.</li> <li>Hence, the answer is 4.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, m = 2, k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 1, 1, 2]</code>, <code>[1, 1, 2, 2]</code>, <code>[1, 2, 2, 2]</code>, <code>[2, 1, 1, 1]</code>, <code>[2, 2, 1, 1]</code> and <code>[2, 2, 2, 1]</code>.</li> <li>Hence, the answer is 6.</li> </ul> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, m = 2, k = 0</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 2, 1, 2, 1]</code> and <code>[2, 1, 2, 1, 2]</code>. Hence, the answer is 2.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= m &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= k &lt;= n - 1</code></li> </ul>
Math; Combinatorics
Java
class Solution { private static final int N = (int) 1e5 + 10; private static final int MOD = (int) 1e9 + 7; private static final long[] f = new long[N]; private static final long[] g = new long[N]; static { f[0] = 1; g[0] = 1; for (int i = 1; i < N; ++i) { f[i] = f[i - 1] * i % MOD; g[i] = qpow(f[i], MOD - 2); } } public static long qpow(long a, int k) { long res = 1; while (k != 0) { if ((k & 1) == 1) { res = res * a % MOD; } k >>= 1; a = a * a % MOD; } return res; } public static long comb(int m, int n) { return (int) f[m] * g[n] % MOD * g[m - n] % MOD; } public int countGoodArrays(int n, int m, int k) { return (int) (comb(n - 1, k) * m % MOD * qpow(m - 1, n - k - 1) % MOD); } }
3,405
Count the Number of Arrays with K Matching Adjacent Elements
Hard
<p>You are given three integers <code>n</code>, <code>m</code>, <code>k</code>. A <strong>good array</strong> <code>arr</code> of size <code>n</code> is defined as follows:</p> <ul> <li>Each element in <code>arr</code> is in the <strong>inclusive</strong> range <code>[1, m]</code>.</li> <li><em>Exactly</em> <code>k</code> indices <code>i</code> (where <code>1 &lt;= i &lt; n</code>) satisfy the condition <code>arr[i - 1] == arr[i]</code>.</li> </ul> <p>Return the number of <strong>good arrays</strong> that can be formed.</p> <p>Since the answer may be very large, return it <strong>modulo </strong><code>10<sup>9 </sup>+ 7</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 3, m = 2, k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <ul> <li>There are 4 good arrays. They are <code>[1, 1, 2]</code>, <code>[1, 2, 2]</code>, <code>[2, 1, 1]</code> and <code>[2, 2, 1]</code>.</li> <li>Hence, the answer is 4.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, m = 2, k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 1, 1, 2]</code>, <code>[1, 1, 2, 2]</code>, <code>[1, 2, 2, 2]</code>, <code>[2, 1, 1, 1]</code>, <code>[2, 2, 1, 1]</code> and <code>[2, 2, 2, 1]</code>.</li> <li>Hence, the answer is 6.</li> </ul> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, m = 2, k = 0</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 2, 1, 2, 1]</code> and <code>[2, 1, 2, 1, 2]</code>. Hence, the answer is 2.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= m &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= k &lt;= n - 1</code></li> </ul>
Math; Combinatorics
Python
mx = 10**5 + 10 mod = 10**9 + 7 f = [1] + [0] * mx g = [1] + [0] * mx for i in range(1, mx): f[i] = f[i - 1] * i % mod g[i] = pow(f[i], mod - 2, mod) def comb(m: int, n: int) -> int: return f[m] * g[n] * g[m - n] % mod class Solution: def countGoodArrays(self, n: int, m: int, k: int) -> int: return comb(n - 1, k) * m * pow(m - 1, n - k - 1, mod) % mod
3,405
Count the Number of Arrays with K Matching Adjacent Elements
Hard
<p>You are given three integers <code>n</code>, <code>m</code>, <code>k</code>. A <strong>good array</strong> <code>arr</code> of size <code>n</code> is defined as follows:</p> <ul> <li>Each element in <code>arr</code> is in the <strong>inclusive</strong> range <code>[1, m]</code>.</li> <li><em>Exactly</em> <code>k</code> indices <code>i</code> (where <code>1 &lt;= i &lt; n</code>) satisfy the condition <code>arr[i - 1] == arr[i]</code>.</li> </ul> <p>Return the number of <strong>good arrays</strong> that can be formed.</p> <p>Since the answer may be very large, return it <strong>modulo </strong><code>10<sup>9 </sup>+ 7</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 3, m = 2, k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <ul> <li>There are 4 good arrays. They are <code>[1, 1, 2]</code>, <code>[1, 2, 2]</code>, <code>[2, 1, 1]</code> and <code>[2, 2, 1]</code>.</li> <li>Hence, the answer is 4.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, m = 2, k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 1, 1, 2]</code>, <code>[1, 1, 2, 2]</code>, <code>[1, 2, 2, 2]</code>, <code>[2, 1, 1, 1]</code>, <code>[2, 2, 1, 1]</code> and <code>[2, 2, 2, 1]</code>.</li> <li>Hence, the answer is 6.</li> </ul> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, m = 2, k = 0</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 2, 1, 2, 1]</code> and <code>[2, 1, 2, 1, 2]</code>. Hence, the answer is 2.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= m &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= k &lt;= n - 1</code></li> </ul>
Math; Combinatorics
Rust
impl Solution { pub fn count_good_arrays(n: i32, m: i32, k: i32) -> i32 { const N: usize = 1e5 as usize + 10; const MOD: i64 = 1_000_000_007; use std::sync::OnceLock; static F: OnceLock<Vec<i64>> = OnceLock::new(); static G: OnceLock<Vec<i64>> = OnceLock::new(); fn qpow(mut a: i64, mut k: i64, m: i64) -> i64 { let mut res = 1; while k != 0 { if k & 1 == 1 { res = res * a % m; } a = a * a % m; k >>= 1; } res } fn init() -> (&'static Vec<i64>, &'static Vec<i64>) { F.get_or_init(|| { let mut f = vec![1i64; N]; for i in 1..N { f[i] = f[i - 1] * i as i64 % MOD; } f }); G.get_or_init(|| { let f = F.get().unwrap(); let mut g = vec![1i64; N]; for i in 1..N { g[i] = qpow(f[i], MOD - 2, MOD); } g }); (F.get().unwrap(), G.get().unwrap()) } fn comb(f: &[i64], g: &[i64], m: usize, n: usize) -> i64 { f[m] * g[n] % MOD * g[m - n] % MOD } let (f, g) = init(); let n = n as usize; let m = m as i64; let k = k as usize; let c = comb(f, g, n - 1, k); let pow = qpow(m - 1, (n - 1 - k) as i64, MOD); (c * m % MOD * pow % MOD) as i32 } }
3,405
Count the Number of Arrays with K Matching Adjacent Elements
Hard
<p>You are given three integers <code>n</code>, <code>m</code>, <code>k</code>. A <strong>good array</strong> <code>arr</code> of size <code>n</code> is defined as follows:</p> <ul> <li>Each element in <code>arr</code> is in the <strong>inclusive</strong> range <code>[1, m]</code>.</li> <li><em>Exactly</em> <code>k</code> indices <code>i</code> (where <code>1 &lt;= i &lt; n</code>) satisfy the condition <code>arr[i - 1] == arr[i]</code>.</li> </ul> <p>Return the number of <strong>good arrays</strong> that can be formed.</p> <p>Since the answer may be very large, return it <strong>modulo </strong><code>10<sup>9 </sup>+ 7</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 3, m = 2, k = 1</span></p> <p><strong>Output:</strong> <span class="example-io">4</span></p> <p><strong>Explanation:</strong></p> <ul> <li>There are 4 good arrays. They are <code>[1, 1, 2]</code>, <code>[1, 2, 2]</code>, <code>[2, 1, 1]</code> and <code>[2, 2, 1]</code>.</li> <li>Hence, the answer is 4.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 4, m = 2, k = 2</span></p> <p><strong>Output:</strong> <span class="example-io">6</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 1, 1, 2]</code>, <code>[1, 1, 2, 2]</code>, <code>[1, 2, 2, 2]</code>, <code>[2, 1, 1, 1]</code>, <code>[2, 2, 1, 1]</code> and <code>[2, 2, 2, 1]</code>.</li> <li>Hence, the answer is 6.</li> </ul> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">n = 5, m = 2, k = 0</span></p> <p><strong>Output:</strong> <span class="example-io">2</span></p> <p><strong>Explanation:</strong></p> <ul> <li>The good arrays are <code>[1, 2, 1, 2, 1]</code> and <code>[2, 1, 2, 1, 2]</code>. Hence, the answer is 2.</li> </ul> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= n &lt;= 10<sup>5</sup></code></li> <li><code>1 &lt;= m &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= k &lt;= n - 1</code></li> </ul>
Math; Combinatorics
TypeScript
const MX = 1e5 + 10; const MOD = BigInt(1e9 + 7); const f: bigint[] = Array(MX).fill(1n); const g: bigint[] = Array(MX).fill(1n); function qpow(a: bigint, k: number): bigint { let res = 1n; while (k !== 0) { if ((k & 1) === 1) { res = (res * a) % MOD; } a = (a * a) % MOD; k >>= 1; } return res; } (function init() { for (let i = 1; i < MX; ++i) { f[i] = (f[i - 1] * BigInt(i)) % MOD; g[i] = qpow(f[i], Number(MOD - 2n)); } })(); function comb(m: number, n: number): bigint { return (((f[m] * g[n]) % MOD) * g[m - n]) % MOD; } export function countGoodArrays(n: number, m: number, k: number): number { const ans = (((comb(n - 1, k) * BigInt(m)) % MOD) * qpow(BigInt(m - 1), n - k - 1)) % MOD; return Number(ans); }
3,406
Find the Lexicographically Largest String From the Box II
Hard
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <strong>lexicographically largest</strong> string from the box after all the rounds are finished.</p> <p>A string <code>a</code> is <strong>lexicographically smaller</strong> than a string <code>b</code> if in the first position where <code>a</code> and <code>b</code> differ, string <code>a</code> has a letter that appears earlier in the alphabet than the corresponding letter in <code>b</code>.<br /> If the first <code>min(a.length, b.length)</code> characters do not differ, then the shorter string is the lexicographically smaller one.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong></p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong></p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 2 * 10<sup>5</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String
C++
class Solution { public: string answerString(string word, int numFriends) { if (numFriends == 1) { return word; } string s = lastSubstring(word); return s.substr(0, min(s.length(), word.length() - numFriends + 1)); } string lastSubstring(string& s) { int n = s.size(); int i = 0, j = 1, k = 0; while (j + k < n) { if (s[i + k] == s[j + k]) { ++k; } else if (s[i + k] < s[j + k]) { i += k + 1; k = 0; if (i >= j) { j = i + 1; } } else { j += k + 1; k = 0; } } return s.substr(i); } };
3,406
Find the Lexicographically Largest String From the Box II
Hard
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <strong>lexicographically largest</strong> string from the box after all the rounds are finished.</p> <p>A string <code>a</code> is <strong>lexicographically smaller</strong> than a string <code>b</code> if in the first position where <code>a</code> and <code>b</code> differ, string <code>a</code> has a letter that appears earlier in the alphabet than the corresponding letter in <code>b</code>.<br /> If the first <code>min(a.length, b.length)</code> characters do not differ, then the shorter string is the lexicographically smaller one.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong></p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong></p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 2 * 10<sup>5</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String
Go
func answerString(word string, numFriends int) string { if numFriends == 1 { return word } s := lastSubstring(word) return s[:min(len(s), len(word)-numFriends+1)] } func lastSubstring(s string) string { n := len(s) i, j, k := 0, 1, 0 for j+k < n { if s[i+k] == s[j+k] { k++ } else if s[i+k] < s[j+k] { i += k + 1 k = 0 if i >= j { j = i + 1 } } else { j += k + 1 k = 0 } } return s[i:] }
3,406
Find the Lexicographically Largest String From the Box II
Hard
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <strong>lexicographically largest</strong> string from the box after all the rounds are finished.</p> <p>A string <code>a</code> is <strong>lexicographically smaller</strong> than a string <code>b</code> if in the first position where <code>a</code> and <code>b</code> differ, string <code>a</code> has a letter that appears earlier in the alphabet than the corresponding letter in <code>b</code>.<br /> If the first <code>min(a.length, b.length)</code> characters do not differ, then the shorter string is the lexicographically smaller one.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong></p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong></p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 2 * 10<sup>5</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String
Java
class Solution { public String answerString(String word, int numFriends) { if (numFriends == 1) { return word; } String s = lastSubstring(word); return s.substring(0, Math.min(s.length(), word.length() - numFriends + 1)); } public String lastSubstring(String s) { int n = s.length(); int i = 0, j = 1, k = 0; while (j + k < n) { int d = s.charAt(i + k) - s.charAt(j + k); if (d == 0) { ++k; } else if (d < 0) { i += k + 1; k = 0; if (i >= j) { j = i + 1; } } else { j += k + 1; k = 0; } } return s.substring(i); } }
3,406
Find the Lexicographically Largest String From the Box II
Hard
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <strong>lexicographically largest</strong> string from the box after all the rounds are finished.</p> <p>A string <code>a</code> is <strong>lexicographically smaller</strong> than a string <code>b</code> if in the first position where <code>a</code> and <code>b</code> differ, string <code>a</code> has a letter that appears earlier in the alphabet than the corresponding letter in <code>b</code>.<br /> If the first <code>min(a.length, b.length)</code> characters do not differ, then the shorter string is the lexicographically smaller one.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong></p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong></p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 2 * 10<sup>5</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String
Python
class Solution: def answerString(self, word: str, numFriends: int) -> str: if numFriends == 1: return word s = self.lastSubstring(word) return s[: len(word) - numFriends + 1] def lastSubstring(self, s: str) -> str: i, j, k = 0, 1, 0 while j + k < len(s): if s[i + k] == s[j + k]: k += 1 elif s[i + k] < s[j + k]: i += k + 1 k = 0 if i >= j: j = i + 1 else: j += k + 1 k = 0 return s[i:]
3,406
Find the Lexicographically Largest String From the Box II
Hard
<p>You are given a string <code>word</code>, and an integer <code>numFriends</code>.</p> <p>Alice is organizing a game for her <code>numFriends</code> friends. There are multiple rounds in the game, where in each round:</p> <ul> <li><code>word</code> is split into <code>numFriends</code> <strong>non-empty</strong> strings, such that no previous round has had the <strong>exact</strong> same split.</li> <li>All the split words are put into a box.</li> </ul> <p>Find the <strong>lexicographically largest</strong> string from the box after all the rounds are finished.</p> <p>A string <code>a</code> is <strong>lexicographically smaller</strong> than a string <code>b</code> if in the first position where <code>a</code> and <code>b</code> differ, string <code>a</code> has a letter that appears earlier in the alphabet than the corresponding letter in <code>b</code>.<br /> If the first <code>min(a.length, b.length)</code> characters do not differ, then the shorter string is the lexicographically smaller one.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;dbca&quot;, numFriends = 2</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;dbc&quot;</span></p> <p><strong>Explanation:</strong></p> <p>All possible splits are:</p> <ul> <li><code>&quot;d&quot;</code> and <code>&quot;bca&quot;</code>.</li> <li><code>&quot;db&quot;</code> and <code>&quot;ca&quot;</code>.</li> <li><code>&quot;dbc&quot;</code> and <code>&quot;a&quot;</code>.</li> </ul> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">word = &quot;gggg&quot;, numFriends = 4</span></p> <p><strong>Output:</strong> <span class="example-io">&quot;g&quot;</span></p> <p><strong>Explanation:</strong></p> <p>The only possible split is: <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, <code>&quot;g&quot;</code>, and <code>&quot;g&quot;</code>.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= word.length &lt;= 2 * 10<sup>5</sup></code></li> <li><code>word</code> consists only of lowercase English letters.</li> <li><code>1 &lt;= numFriends &lt;= word.length</code></li> </ul>
Two Pointers; String
TypeScript
function answerString(word: string, numFriends: number): string { if (numFriends === 1) { return word; } const s = lastSubstring(word); return s.slice(0, word.length - numFriends + 1); } function lastSubstring(s: string): string { const n = s.length; let i = 0; for (let j = 1, k = 0; j + k < n; ) { if (s[i + k] === s[j + k]) { ++k; } else if (s[i + k] < s[j + k]) { i += k + 1; k = 0; if (i >= j) { j = i + 1; } } else { j += k + 1; k = 0; } } return s.slice(i); }
3,407
Substring Matching Pattern
Easy
<p>You are given a string <code>s</code> and a pattern string <code>p</code>, where <code>p</code> contains <strong>exactly one</strong> <code>&#39;*&#39;</code> character.</p> <p>The <code>&#39;*&#39;</code> in <code>p</code> can be replaced with any sequence of zero or more characters.</p> <p>Return <code>true</code> if <code>p</code> can be made a <span data-keyword="substring-nonempty">substring</span> of <code>s</code>, and <code>false</code> otherwise.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;leetcode&quot;, p = &quot;ee*e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>By replacing the <code>&#39;*&#39;</code> with <code>&quot;tcod&quot;</code>, the substring <code>&quot;eetcode&quot;</code> matches the pattern.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;car&quot;, p = &quot;c*v&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>There is no substring matching the pattern.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;luck&quot;, p = &quot;u*&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>The substrings <code>&quot;u&quot;</code>, <code>&quot;uc&quot;</code>, and <code>&quot;uck&quot;</code> match the pattern.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 50</code></li> <li><code>1 &lt;= p.length &lt;= 50 </code></li> <li><code>s</code> contains only lowercase English letters.</li> <li><code>p</code> contains only lowercase English letters and exactly one <code>&#39;*&#39;</code></li> </ul>
String; String Matching
C++
class Solution { public: bool hasMatch(string s, string p) { int i = 0; int pos = 0; int start = 0, end; while ((end = p.find("*", start)) != string::npos) { string t = p.substr(start, end - start); pos = s.find(t, i); if (pos == string::npos) { return false; } i = pos + t.length(); start = end + 1; } string t = p.substr(start); pos = s.find(t, i); if (pos == string::npos) { return false; } return true; } };
3,407
Substring Matching Pattern
Easy
<p>You are given a string <code>s</code> and a pattern string <code>p</code>, where <code>p</code> contains <strong>exactly one</strong> <code>&#39;*&#39;</code> character.</p> <p>The <code>&#39;*&#39;</code> in <code>p</code> can be replaced with any sequence of zero or more characters.</p> <p>Return <code>true</code> if <code>p</code> can be made a <span data-keyword="substring-nonempty">substring</span> of <code>s</code>, and <code>false</code> otherwise.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;leetcode&quot;, p = &quot;ee*e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>By replacing the <code>&#39;*&#39;</code> with <code>&quot;tcod&quot;</code>, the substring <code>&quot;eetcode&quot;</code> matches the pattern.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;car&quot;, p = &quot;c*v&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>There is no substring matching the pattern.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;luck&quot;, p = &quot;u*&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>The substrings <code>&quot;u&quot;</code>, <code>&quot;uc&quot;</code>, and <code>&quot;uck&quot;</code> match the pattern.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 50</code></li> <li><code>1 &lt;= p.length &lt;= 50 </code></li> <li><code>s</code> contains only lowercase English letters.</li> <li><code>p</code> contains only lowercase English letters and exactly one <code>&#39;*&#39;</code></li> </ul>
String; String Matching
Go
func hasMatch(s string, p string) bool { i := 0 for _, t := range strings.Split(p, "*") { j := strings.Index(s[i:], t) if j == -1 { return false } i += j + len(t) } return true }
3,407
Substring Matching Pattern
Easy
<p>You are given a string <code>s</code> and a pattern string <code>p</code>, where <code>p</code> contains <strong>exactly one</strong> <code>&#39;*&#39;</code> character.</p> <p>The <code>&#39;*&#39;</code> in <code>p</code> can be replaced with any sequence of zero or more characters.</p> <p>Return <code>true</code> if <code>p</code> can be made a <span data-keyword="substring-nonempty">substring</span> of <code>s</code>, and <code>false</code> otherwise.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;leetcode&quot;, p = &quot;ee*e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>By replacing the <code>&#39;*&#39;</code> with <code>&quot;tcod&quot;</code>, the substring <code>&quot;eetcode&quot;</code> matches the pattern.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;car&quot;, p = &quot;c*v&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>There is no substring matching the pattern.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;luck&quot;, p = &quot;u*&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>The substrings <code>&quot;u&quot;</code>, <code>&quot;uc&quot;</code>, and <code>&quot;uck&quot;</code> match the pattern.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 50</code></li> <li><code>1 &lt;= p.length &lt;= 50 </code></li> <li><code>s</code> contains only lowercase English letters.</li> <li><code>p</code> contains only lowercase English letters and exactly one <code>&#39;*&#39;</code></li> </ul>
String; String Matching
Java
class Solution { public boolean hasMatch(String s, String p) { int i = 0; for (String t : p.split("\\*")) { int j = s.indexOf(t, i); if (j == -1) { return false; } i = j + t.length(); } return true; } }
3,407
Substring Matching Pattern
Easy
<p>You are given a string <code>s</code> and a pattern string <code>p</code>, where <code>p</code> contains <strong>exactly one</strong> <code>&#39;*&#39;</code> character.</p> <p>The <code>&#39;*&#39;</code> in <code>p</code> can be replaced with any sequence of zero or more characters.</p> <p>Return <code>true</code> if <code>p</code> can be made a <span data-keyword="substring-nonempty">substring</span> of <code>s</code>, and <code>false</code> otherwise.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;leetcode&quot;, p = &quot;ee*e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>By replacing the <code>&#39;*&#39;</code> with <code>&quot;tcod&quot;</code>, the substring <code>&quot;eetcode&quot;</code> matches the pattern.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;car&quot;, p = &quot;c*v&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>There is no substring matching the pattern.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;luck&quot;, p = &quot;u*&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>The substrings <code>&quot;u&quot;</code>, <code>&quot;uc&quot;</code>, and <code>&quot;uck&quot;</code> match the pattern.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 50</code></li> <li><code>1 &lt;= p.length &lt;= 50 </code></li> <li><code>s</code> contains only lowercase English letters.</li> <li><code>p</code> contains only lowercase English letters and exactly one <code>&#39;*&#39;</code></li> </ul>
String; String Matching
Python
class Solution: def hasMatch(self, s: str, p: str) -> bool: i = 0 for t in p.split("*"): j = s.find(t, i) if j == -1: return False i = j + len(t) return True
3,407
Substring Matching Pattern
Easy
<p>You are given a string <code>s</code> and a pattern string <code>p</code>, where <code>p</code> contains <strong>exactly one</strong> <code>&#39;*&#39;</code> character.</p> <p>The <code>&#39;*&#39;</code> in <code>p</code> can be replaced with any sequence of zero or more characters.</p> <p>Return <code>true</code> if <code>p</code> can be made a <span data-keyword="substring-nonempty">substring</span> of <code>s</code>, and <code>false</code> otherwise.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;leetcode&quot;, p = &quot;ee*e&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>By replacing the <code>&#39;*&#39;</code> with <code>&quot;tcod&quot;</code>, the substring <code>&quot;eetcode&quot;</code> matches the pattern.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;car&quot;, p = &quot;c*v&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">false</span></p> <p><strong>Explanation:</strong></p> <p>There is no substring matching the pattern.</p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">s = &quot;luck&quot;, p = &quot;u*&quot;</span></p> <p><strong>Output:</strong> <span class="example-io">true</span></p> <p><strong>Explanation:</strong></p> <p>The substrings <code>&quot;u&quot;</code>, <code>&quot;uc&quot;</code>, and <code>&quot;uck&quot;</code> match the pattern.</p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= s.length &lt;= 50</code></li> <li><code>1 &lt;= p.length &lt;= 50 </code></li> <li><code>s</code> contains only lowercase English letters.</li> <li><code>p</code> contains only lowercase English letters and exactly one <code>&#39;*&#39;</code></li> </ul>
String; String Matching
TypeScript
function hasMatch(s: string, p: string): boolean { let i = 0; for (const t of p.split('*')) { const j = s.indexOf(t, i); if (j === -1) { return false; } i = j + t.length; } return true; }
3,408
Design Task Manager
Medium
<p>There is a task management system that allows users to manage their tasks, each associated with a priority. The system should efficiently handle adding, modifying, executing, and removing tasks.</p> <p>Implement the <code>TaskManager</code> class:</p> <ul> <li> <p><code>TaskManager(vector&lt;vector&lt;int&gt;&gt;&amp; tasks)</code> initializes the task manager with a list of user-task-priority triples. Each element in the input list is of the form <code>[userId, taskId, priority]</code>, which adds a task to the specified user with the given priority.</p> </li> <li> <p><code>void add(int userId, int taskId, int priority)</code> adds a task with the specified <code>taskId</code> and <code>priority</code> to the user with <code>userId</code>. It is <strong>guaranteed</strong> that <code>taskId</code> does not <em>exist</em> in the system.</p> </li> <li> <p><code>void edit(int taskId, int newPriority)</code> updates the priority of the existing <code>taskId</code> to <code>newPriority</code>. It is <strong>guaranteed</strong> that <code>taskId</code> <em>exists</em> in the system.</p> </li> <li> <p><code>void rmv(int taskId)</code> removes the task identified by <code>taskId</code> from the system. It is <strong>guaranteed</strong> that <code>taskId</code> <em>exists</em> in the system.</p> </li> <li> <p><code>int execTop()</code> executes the task with the <strong>highest</strong> priority across all users. If there are multiple tasks with the same <strong>highest</strong> priority, execute the one with the highest <code>taskId</code>. After executing, the<strong> </strong><code>taskId</code><strong> </strong>is <strong>removed</strong> from the system. Return the <code>userId</code> associated with the executed task. If no tasks are available, return -1.</p> </li> </ul> <p><strong>Note</strong> that a user may be assigned multiple tasks.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;TaskManager&quot;, &quot;add&quot;, &quot;edit&quot;, &quot;execTop&quot;, &quot;rmv&quot;, &quot;add&quot;, &quot;execTop&quot;]<br /> [[[[1, 101, 10], [2, 102, 20], [3, 103, 15]]], [4, 104, 5], [102, 8], [], [101], [5, 105, 15], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, null, 3, null, null, 5] </span></p> <p><strong>Explanation</strong></p> TaskManager taskManager = new TaskManager([[1, 101, 10], [2, 102, 20], [3, 103, 15]]); // Initializes with three tasks for Users 1, 2, and 3.<br /> taskManager.add(4, 104, 5); // Adds task 104 with priority 5 for User 4.<br /> taskManager.edit(102, 8); // Updates priority of task 102 to 8.<br /> taskManager.execTop(); // return 3. Executes task 103 for User 3.<br /> taskManager.rmv(101); // Removes task 101 from the system.<br /> taskManager.add(5, 105, 15); // Adds task 105 with priority 15 for User 5.<br /> taskManager.execTop(); // return 5. Executes task 105 for User 5.</div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= tasks.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= userId &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= taskId &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= priority &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= newPriority &lt;= 10<sup>9</sup></code></li> <li>At most <code>2 * 10<sup>5</sup></code> calls will be made in <strong>total</strong> to <code>add</code>, <code>edit</code>, <code>rmv</code>, and <code>execTop</code> methods.</li> <li>The input is generated such that <code>taskId</code> will be valid.</li> </ul>
Design; Hash Table; Ordered Set; Heap (Priority Queue)
C++
class TaskManager { private: unordered_map<int, pair<int, int>> d; set<pair<int, int>> st; public: TaskManager(vector<vector<int>>& tasks) { for (const auto& task : tasks) { add(task[0], task[1], task[2]); } } void add(int userId, int taskId, int priority) { d[taskId] = {userId, priority}; st.insert({-priority, -taskId}); } void edit(int taskId, int newPriority) { auto [userId, priority] = d[taskId]; st.erase({-priority, -taskId}); st.insert({-newPriority, -taskId}); d[taskId] = {userId, newPriority}; } void rmv(int taskId) { auto [userId, priority] = d[taskId]; st.erase({-priority, -taskId}); d.erase(taskId); } int execTop() { if (st.empty()) { return -1; } auto e = *st.begin(); st.erase(st.begin()); int taskId = -e.second; int userId = d[taskId].first; d.erase(taskId); return userId; } }; /** * Your TaskManager object will be instantiated and called as such: * TaskManager* obj = new TaskManager(tasks); * obj->add(userId,taskId,priority); * obj->edit(taskId,newPriority); * obj->rmv(taskId); * int param_4 = obj->execTop(); */
3,408
Design Task Manager
Medium
<p>There is a task management system that allows users to manage their tasks, each associated with a priority. The system should efficiently handle adding, modifying, executing, and removing tasks.</p> <p>Implement the <code>TaskManager</code> class:</p> <ul> <li> <p><code>TaskManager(vector&lt;vector&lt;int&gt;&gt;&amp; tasks)</code> initializes the task manager with a list of user-task-priority triples. Each element in the input list is of the form <code>[userId, taskId, priority]</code>, which adds a task to the specified user with the given priority.</p> </li> <li> <p><code>void add(int userId, int taskId, int priority)</code> adds a task with the specified <code>taskId</code> and <code>priority</code> to the user with <code>userId</code>. It is <strong>guaranteed</strong> that <code>taskId</code> does not <em>exist</em> in the system.</p> </li> <li> <p><code>void edit(int taskId, int newPriority)</code> updates the priority of the existing <code>taskId</code> to <code>newPriority</code>. It is <strong>guaranteed</strong> that <code>taskId</code> <em>exists</em> in the system.</p> </li> <li> <p><code>void rmv(int taskId)</code> removes the task identified by <code>taskId</code> from the system. It is <strong>guaranteed</strong> that <code>taskId</code> <em>exists</em> in the system.</p> </li> <li> <p><code>int execTop()</code> executes the task with the <strong>highest</strong> priority across all users. If there are multiple tasks with the same <strong>highest</strong> priority, execute the one with the highest <code>taskId</code>. After executing, the<strong> </strong><code>taskId</code><strong> </strong>is <strong>removed</strong> from the system. Return the <code>userId</code> associated with the executed task. If no tasks are available, return -1.</p> </li> </ul> <p><strong>Note</strong> that a user may be assigned multiple tasks.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;TaskManager&quot;, &quot;add&quot;, &quot;edit&quot;, &quot;execTop&quot;, &quot;rmv&quot;, &quot;add&quot;, &quot;execTop&quot;]<br /> [[[[1, 101, 10], [2, 102, 20], [3, 103, 15]]], [4, 104, 5], [102, 8], [], [101], [5, 105, 15], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, null, 3, null, null, 5] </span></p> <p><strong>Explanation</strong></p> TaskManager taskManager = new TaskManager([[1, 101, 10], [2, 102, 20], [3, 103, 15]]); // Initializes with three tasks for Users 1, 2, and 3.<br /> taskManager.add(4, 104, 5); // Adds task 104 with priority 5 for User 4.<br /> taskManager.edit(102, 8); // Updates priority of task 102 to 8.<br /> taskManager.execTop(); // return 3. Executes task 103 for User 3.<br /> taskManager.rmv(101); // Removes task 101 from the system.<br /> taskManager.add(5, 105, 15); // Adds task 105 with priority 15 for User 5.<br /> taskManager.execTop(); // return 5. Executes task 105 for User 5.</div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= tasks.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= userId &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= taskId &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= priority &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= newPriority &lt;= 10<sup>9</sup></code></li> <li>At most <code>2 * 10<sup>5</sup></code> calls will be made in <strong>total</strong> to <code>add</code>, <code>edit</code>, <code>rmv</code>, and <code>execTop</code> methods.</li> <li>The input is generated such that <code>taskId</code> will be valid.</li> </ul>
Design; Hash Table; Ordered Set; Heap (Priority Queue)
Java
class TaskManager { private final Map<Integer, int[]> d = new HashMap<>(); private final TreeSet<int[]> st = new TreeSet<>((a, b) -> { if (a[0] == b[0]) { return b[1] - a[1]; } return b[0] - a[0]; }); public TaskManager(List<List<Integer>> tasks) { for (var task : tasks) { add(task.get(0), task.get(1), task.get(2)); } } public void add(int userId, int taskId, int priority) { d.put(taskId, new int[] {userId, priority}); st.add(new int[] {priority, taskId}); } public void edit(int taskId, int newPriority) { var e = d.get(taskId); int userId = e[0], priority = e[1]; st.remove(new int[] {priority, taskId}); st.add(new int[] {newPriority, taskId}); d.put(taskId, new int[] {userId, newPriority}); } public void rmv(int taskId) { var e = d.remove(taskId); int priority = e[1]; st.remove(new int[] {priority, taskId}); } public int execTop() { if (st.isEmpty()) { return -1; } var e = st.pollFirst(); var t = d.remove(e[1]); return t[0]; } } /** * Your TaskManager object will be instantiated and called as such: * TaskManager obj = new TaskManager(tasks); * obj.add(userId,taskId,priority); * obj.edit(taskId,newPriority); * obj.rmv(taskId); * int param_4 = obj.execTop(); */
3,408
Design Task Manager
Medium
<p>There is a task management system that allows users to manage their tasks, each associated with a priority. The system should efficiently handle adding, modifying, executing, and removing tasks.</p> <p>Implement the <code>TaskManager</code> class:</p> <ul> <li> <p><code>TaskManager(vector&lt;vector&lt;int&gt;&gt;&amp; tasks)</code> initializes the task manager with a list of user-task-priority triples. Each element in the input list is of the form <code>[userId, taskId, priority]</code>, which adds a task to the specified user with the given priority.</p> </li> <li> <p><code>void add(int userId, int taskId, int priority)</code> adds a task with the specified <code>taskId</code> and <code>priority</code> to the user with <code>userId</code>. It is <strong>guaranteed</strong> that <code>taskId</code> does not <em>exist</em> in the system.</p> </li> <li> <p><code>void edit(int taskId, int newPriority)</code> updates the priority of the existing <code>taskId</code> to <code>newPriority</code>. It is <strong>guaranteed</strong> that <code>taskId</code> <em>exists</em> in the system.</p> </li> <li> <p><code>void rmv(int taskId)</code> removes the task identified by <code>taskId</code> from the system. It is <strong>guaranteed</strong> that <code>taskId</code> <em>exists</em> in the system.</p> </li> <li> <p><code>int execTop()</code> executes the task with the <strong>highest</strong> priority across all users. If there are multiple tasks with the same <strong>highest</strong> priority, execute the one with the highest <code>taskId</code>. After executing, the<strong> </strong><code>taskId</code><strong> </strong>is <strong>removed</strong> from the system. Return the <code>userId</code> associated with the executed task. If no tasks are available, return -1.</p> </li> </ul> <p><strong>Note</strong> that a user may be assigned multiple tasks.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong><br /> <span class="example-io">[&quot;TaskManager&quot;, &quot;add&quot;, &quot;edit&quot;, &quot;execTop&quot;, &quot;rmv&quot;, &quot;add&quot;, &quot;execTop&quot;]<br /> [[[[1, 101, 10], [2, 102, 20], [3, 103, 15]]], [4, 104, 5], [102, 8], [], [101], [5, 105, 15], []]</span></p> <p><strong>Output:</strong><br /> <span class="example-io">[null, null, null, 3, null, null, 5] </span></p> <p><strong>Explanation</strong></p> TaskManager taskManager = new TaskManager([[1, 101, 10], [2, 102, 20], [3, 103, 15]]); // Initializes with three tasks for Users 1, 2, and 3.<br /> taskManager.add(4, 104, 5); // Adds task 104 with priority 5 for User 4.<br /> taskManager.edit(102, 8); // Updates priority of task 102 to 8.<br /> taskManager.execTop(); // return 3. Executes task 103 for User 3.<br /> taskManager.rmv(101); // Removes task 101 from the system.<br /> taskManager.add(5, 105, 15); // Adds task 105 with priority 15 for User 5.<br /> taskManager.execTop(); // return 5. Executes task 105 for User 5.</div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 &lt;= tasks.length &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= userId &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= taskId &lt;= 10<sup>5</sup></code></li> <li><code>0 &lt;= priority &lt;= 10<sup>9</sup></code></li> <li><code>0 &lt;= newPriority &lt;= 10<sup>9</sup></code></li> <li>At most <code>2 * 10<sup>5</sup></code> calls will be made in <strong>total</strong> to <code>add</code>, <code>edit</code>, <code>rmv</code>, and <code>execTop</code> methods.</li> <li>The input is generated such that <code>taskId</code> will be valid.</li> </ul>
Design; Hash Table; Ordered Set; Heap (Priority Queue)
Python
class TaskManager: def __init__(self, tasks: List[List[int]]): self.d = {} self.st = SortedList() for task in tasks: self.add(*task) def add(self, userId: int, taskId: int, priority: int) -> None: self.d[taskId] = (userId, priority) self.st.add((-priority, -taskId)) def edit(self, taskId: int, newPriority: int) -> None: userId, priority = self.d[taskId] self.st.discard((-priority, -taskId)) self.d[taskId] = (userId, newPriority) self.st.add((-newPriority, -taskId)) def rmv(self, taskId: int) -> None: _, priority = self.d[taskId] self.d.pop(taskId) self.st.remove((-priority, -taskId)) def execTop(self) -> int: if not self.st: return -1 taskId = -self.st.pop(0)[1] userId, _ = self.d[taskId] self.d.pop(taskId) return userId # Your TaskManager object will be instantiated and called as such: # obj = TaskManager(tasks) # obj.add(userId,taskId,priority) # obj.edit(taskId,newPriority) # obj.rmv(taskId) # param_4 = obj.execTop()
3,411
Maximum Subarray With Equal Products
Easy
<p>You are given an array of <strong>positive</strong> integers <code>nums</code>.</p> <p>An array <code>arr</code> is called <strong>product equivalent</strong> if <code>prod(arr) == lcm(arr) * gcd(arr)</code>, where:</p> <ul> <li><code>prod(arr)</code> is the product of all elements of <code>arr</code>.</li> <li><code>gcd(arr)</code> is the <span data-keyword="gcd-function">GCD</span> of all elements of <code>arr</code>.</li> <li><code>lcm(arr)</code> is the <span data-keyword="lcm-function">LCM</span> of all elements of <code>arr</code>.</li> </ul> <p>Return the length of the <strong>longest</strong> <strong>product equivalent</strong> <span data-keyword="subarray-nonempty">subarray</span> of <code>nums</code>.</p> <p>&nbsp;</p> <p><strong class="example">Example 1:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,1,2,1,1,1]</span></p> <p><strong>Output:</strong> <span class="example-io">5</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>The longest product equivalent subarray is <code>[1, 2, 1, 1, 1]</code>, where&nbsp;<code>prod([1, 2, 1, 1, 1]) = 2</code>,&nbsp;<code>gcd([1, 2, 1, 1, 1]) = 1</code>, and&nbsp;<code>lcm([1, 2, 1, 1, 1]) = 2</code>.</p> </div> <p><strong class="example">Example 2:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [2,3,4,5,6]</span></p> <p><strong>Output:</strong> <span class="example-io">3</span></p> <p><strong>Explanation:</strong>&nbsp;</p> <p>The longest product equivalent subarray is <code>[3, 4, 5].</code></p> </div> <p><strong class="example">Example 3:</strong></p> <div class="example-block"> <p><strong>Input:</strong> <span class="example-io">nums = [1,2,3,1,4,5,1]</span></p> <p><strong>Output:</strong> <span class="example-io">5</span></p> </div> <p>&nbsp;</p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 &lt;= nums.length &lt;= 100</code></li> <li><code>1 &lt;= nums[i] &lt;= 10</code></li> </ul>
Array; Math; Enumeration; Number Theory; Sliding Window
C++
class Solution { public: int maxLength(vector<int>& nums) { int mx = 0, ml = 1; for (int x : nums) { mx = max(mx, x); ml = lcm(ml, x); } long long maxP = (long long) ml * mx; int n = nums.size(); int ans = 0; for (int i = 0; i < n; ++i) { long long p = 1, g = 0, l = 1; for (int j = i; j < n; ++j) { p *= nums[j]; g = gcd(g, nums[j]); l = lcm(l, nums[j]); if (p == g * l) { ans = max(ans, j - i + 1); } if (p > maxP) { break; } } } return ans; } };