text: Sum of bitwise AND of all submatrices | Java program to find sum of Bit - wise AND of all submatrices ; Function to find prefix - count for each row from right to left ; Function to find the number of submatrices with all 1 s ; Array to store required prefix count of 1 s from right to left for boolean array ; Variable to store the final answer ; For each index of a column , determine the number of sub - matrices starting from that index and has all 1 s ; Stack to store elements and the count of the numbers they popped First part of pair is value of inserted element Second part is count of the number of elements pushed before with a greater value ; variable to store the number of submatrices with all 1 s ; Function to find sum of Bitwise - OR of all submatrices ; matrix to store the status of ith bit of each element of matrix arr ; Driver Code
code: import java . util . * ; class GFG { static int n = 3 ; static void findPrefixCount ( int p_arr [ ] [ ] , boolean set_bit [ ] [ ] ) { for ( int i = 0 ; i < n ; i ++ ) { for ( int j = n - 1 ; j >= 0 ; j -- ) { if ( ! set_bit [ i ] [ j ] ) continue ; if ( j != n - 1 ) p_arr [ i ] [ j ] += p_arr [ i ] [ j + 1 ] ; p_arr [ i ] [ j ] += ( set_bit [ i ] [ j ] ) ? 1 : 0 ; } } } static class pair { int first , second ; pair ( ) { } pair ( int a , int b ) { first = a ; second = b ; } } static int matrixAllOne ( boolean set_bit [ ] [ ] ) { int p_arr [ ] [ ] = new int [ n ] [ n ] ; for ( int i = 0 ; i < n ; i ++ ) for ( int j = 0 ; j < n ; j ++ ) p_arr [ i ] [ j ] = 0 ; findPrefixCount ( p_arr , set_bit ) ; int ans = 0 ; for ( int j = 0 ; j < n ; j ++ ) { int i = n - 1 ; Stack < pair > q = new Stack < pair > ( ) ; int to_sum = 0 ; while ( i >= 0 ) { int c = 0 ; while ( q . size ( ) != 0 && q . peek ( ) . first > p_arr [ i ] [ j ] ) { to_sum -= ( q . peek ( ) . second + 1 ) * ( q . peek ( ) . first - p_arr [ i ] [ j ] ) ; c += q . peek ( ) . second + 1 ; q . pop ( ) ; } to_sum += p_arr [ i ] [ j ] ; ans += to_sum ; q . push ( new pair ( p_arr [ i ] [ j ] , c ) ) ; i -- ; } } return ans ; } static int sumAndMatrix ( int arr [ ] [ ] ) { int sum = 0 ; int mul = 1 ; for ( int i = 0 ; i < 30 ; i ++ ) { boolean set_bit [ ] [ ] = new boolean [ n ] [ n ] ; for ( int R = 0 ; R < n ; R ++ ) for ( int C = 0 ; C < n ; C ++ ) set_bit [ R ] [ C ] = ( ( arr [ R ] [ C ] & ( 1 << i ) ) != 0 ) ; sum += ( mul * matrixAllOne ( set_bit ) ) ; mul *= 2 ; } return sum ; } public static void main ( String args [ ] ) { int arr [ ] [ ] = { { 9 , 7 , 4 } , { 8 , 9 , 2 } , { 11 , 11 , 5 } } ; System . out . println ( sumAndMatrix ( arr ) ) ; } }