text: Nth number in a set of multiples of A , B or C | C # program to find nth term divisible by a , b or c ; Function to return gcd of a and b ; Function to return the count of integers from the range [ 1 , num ] which are divisible by either a , b or c ; Calculate the number of terms divisible by a , b and c then remove the terms which are divisible by both ( a , b ) or ( b , c ) or ( c , a ) and then add the numbers which are divisible by a , b and c ; Function for binary search to find the nth term divisible by a , b or c ; Set low to 1 and high to LONG_MAX ; If the current term is less than n then we need to increase low to mid + 1 ; If current term is greater than equal to n then high = mid ; Driver code
code: using System ; class GFG { static long gcd ( long a , long b ) { if ( a == 0 ) { return b ; } return gcd ( b % a , a ) ; } static long divTermCount ( long a , long b , long c , long num ) { return ( ( num / a ) + ( num / b ) + ( num / c ) - ( num / ( ( a * b ) / gcd ( a , b ) ) ) - ( num / ( ( c * b ) / gcd ( c , b ) ) ) - ( num / ( ( a * c ) / gcd ( a , c ) ) ) + ( num / ( ( a * b * c ) / gcd ( gcd ( a , b ) , c ) ) ) ) ; } static long findNthTerm ( int a , int b , int c , long n ) { long low = 1 , high = long . MaxValue , mid ; while ( low < high ) { mid = low + ( high - low ) / 2 ; if ( divTermCount ( a , b , c , mid ) < n ) { low = mid + 1 ; } else { high = mid ; } } return low ; } public static void Main ( String [ ] args ) { int a = 2 , b = 3 , c = 5 , n = 100 ; Console . WriteLine ( findNthTerm ( a , b , c , n ) ) ; } }