func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     int t;     cin >> t;     while (t--) {       int n, m, a, b;       cin >> n >> m >> a >> b;       int total_ones = n * a;       if (total_ones != m * b) {         cout <<  NO  << endl;       } else {         cout <<  YES  << endl;         string str =   ;         for (int i = 0; i < m; i++) {           if (i < a)             str +=  1 ;           else             str +=  0 ;         }         for (int i = 0; i < n; i++) {           cout << str << endl;           for (int j = 0; j < a; j++) {             char c = str[0];             str = str.substr(1);             str = str + c;           }         }       }     }   }   