func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int T, n, i, j, k;     cin >> T;     while (T--) {       cin >> n;       string str[51];       for (i = 0; i < n; i++) {         cin >> str[i];       }       if (n == 1) {         cout <<  YES  << endl;         continue;       }       for (i = n - 1; i >= 0; i--) {         for (j = n - 1; j >= 0; j--) {           if (str[i][j] ==  1 ) {             if (i == n - 1 || j == n - 1) str[i][j] =  * ;             k = n - 1;             int c = 0;             while (k >= 0) {               if (str[k][j] ==  * ) {                 c = 1;               } else if (str[k][j] ==  1  && c == 1) {                 str[k][j] =  * ;               } else if (str[k][j] ==  0 )                 c = 0;               k--;             }             k = n - 1;             c = 0;             while (k >= 0) {               if (str[i][k] ==  * ) {                 c = 1;               } else if (str[i][k] ==  1  && c == 1) {                 str[i][k] =  * ;               } else if (str[i][k] ==  0 )                 c = 0;               k--;             }           }         }       }       for (i = n - 1; i >= 0; i--) {         for (j = n - 1; j >= 0; j--) {           if (str[i][j] ==  1 ) {             if (i == n - 1 || j == n - 1) str[i][j] =  * ;             k = n - 1;             int c = 0;             while (k >= 0) {               if (str[i][k] ==  * ) {                 c = 1;               } else if (str[i][k] ==  1  && c == 1) {                 str[i][k] =  * ;               } else if (str[i][k] ==  0 )                 c = 0;               k--;             }             k = n - 1;             c = 0;             while (k >= 0) {               if (str[k][j] ==  * ) {                 c = 1;               } else if (str[k][j] ==  1  && c == 1) {                 str[k][j] =  * ;               } else if (str[k][j] ==  0 )                 c = 0;               k--;             }           }         }       }       int cnt = 0;       for (i = 0; i < n; i++) {         for (j = 0; j < n; j++) {           if (str[i][j] ==  1 ) {             cnt++;           }         }       }       if (cnt == 0)         cout <<  YES  << endl;       else         cout <<  NO  << endl;     }     return 0;   }   