#include <iostream> #include <cstring> using namespace std; const int N = 35; int a[N][N]; bool vis[N][N]; int m; int dx[] = {-1, 1, 0, 0}; int dy[] = {0, 0, -1, 1}; bool ok; void dfs(int x, int y) { if (x == m-1 && y == m-1) { ok = true; return; } for (int d = 0; d < 4; ++d) { int nx = x + dx[d]; int ny = y + dy[d]; if (nx >= 0 && nx < m && ny >= 0 && ny < m) { if (a[nx][ny] == 1 && !vis[nx][ny]) { vis[nx][ny] = true; dfs(nx, ny); if (ok) return; } } } } int main() { int n; cin >> n; while (n--) { cin >> m; for (int i = 0; i < m; ++i) { for (int j = 0; j < m; ++j) { cin >> a[i][j]; } } memset(vis, 0, sizeof(vis)); ok = false; vis[0][0] = true; dfs(0, 0); cout << (ok ? "YES" : "NO") << endl; } return 0; }