func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n, m, a, b;       cin >> n >> m >> a >> b;       if (n * a != m * b) {         cout <<  NO  << endl;         continue;       }       int index = 0;       cout <<  YES  << endl;       for (int i = 0; i < n; ++i) {         for (int j = 0; j < m; ++j) {           cout << ((index + j) % m < a ? 1 : 0);         }         index -= a;         if (index < 0) index += m;         cout << endl;       }     }     return 0;   }   