CF 1360E-Polygon,1300,思维题

CF 1360E-Polygon
如果一个 1 不是在最右边或最下边，则一定有一个 1 在他的紧邻着的下边或右边，否则不合法。
太妙了。

#include <iostream>

using namespace std;

const int N = 1e2 + 10;

int T, n;
char a[N][N];

int main()
{
    cin >> T;
    while (T -- )
    {
        cin >> n;
        
        for (int i = 1; i <= n; i ++ )
        {
            for (int j = 1; j <= n; j ++ )
            {
                cin >> a[i][j];
            }
        }
        
        int flag = 1;
        for (int i = 1; i <= n; i ++ )
        {
            for (int j = 1; j <= n; j ++ )
            {
                if (a[i][j] == '1')
                {
                    if (i == n || j == n) continue;
                    if (a[i + 1][j] == '1' || a[i][j + 1] == '1') continue;
                    flag = 0;
                }
            }
        }
        
        if (flag == 1) cout << "YES\n";
        else cout << "NO\n";
    }
    
    return 0;
}