func_code_string: #include <bits/stdc++.h>   using namespace std;   int a[100][100], n, row[55][100005], col[55][100005];   bool valid(int i, int j) {     for (int k = 0; k < n; k++) {       if (k == i) continue;       int x = a[i][j] - a[k][j];       if (x > 0 && row[i][x] && (x != a[i][j] || row[i][x] > 1)) return 1;     }     return 0;   }   int main() {     scanf( %d , &n);     for (int i = 0; i < n; i++)       for (int j = 0; j < n; j++) {         scanf( %d , &a[i][j]);         row[i][a[i][j]]++;         col[j][a[i][j]]++;       }     for (int i = 0; i < n; i++)       for (int j = 0; j < n; j++)         if (a[i][j] != 1 && !valid(i, j)) {           printf( No n );           return 0;         }     printf( Yes n );   }   