Function to find prefix - count for each row from right to left
void findPrefixCount ( int p_arr [ ] [ n ] , bool set_bit [ ] [ n ] ) { 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 ] += ( int ) ( ! set_bit [ i ] [ j ] ) ; } } }