#include int t, n, mat[15][15]; int main() { scanf("%d", &t); while (t--) { scanf("%d", &n); for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { scanf("%d", &mat[i][j]); } } int flag = 1; for (int i = 1; i <= n; i++) { for (int j = 1; j < i; j++) { if (mat[i][j] != 0) { flag = 0; } } } if (flag) { printf("YES\n"); } else { printf("NO\n"); } } return 0; }