1 #include<stdio.h>
2
3 int main(void)
4 {
5 int t;
6 scanf_s("%d", &t);
7
8 for (int i = 0; i < t; i++)
9 {
10 int n;
11 int a[10][10];
12
13 scanf_s("%d", &n);
14 for (int j = 0; j < n; j++)
15 {
16 for (int k = 0; k < n; k++)
17 {
18 scanf_s("%d", &a[j][k]);
19 }
20 }
21
22 int flag = 0; //标志位
23 for (int j = 0; j < n; j++)
24 {
25 for (int k = 0; k < j; k++)
26 {
27 if (a[j][k] != 0)
28 {
29 flag = 1;
30 break;
31 }
32 }
33 }
34 if (flag == 0)
35 {
36 printf("YES\n");
37 }
38 else
39 {
40 printf("NO\n");
41 }
42 }
43 return 0;
44 }
