矩阵游戏 ZJOI

#include<iostream>
#include<cstring>
#include<cstdio>
#include<vector>
using namespace std;
const int maxn = 300;
int t;
int n;
vector<int>G[maxn];
void add(int x, int y) {
	G[x].push_back(y);
}


int vis[maxn];
int match[maxn];
int dfs(int x) {
	for (int i = 0; i < G[x].size(); i++) {
		int p = G[x][i];
		if (!vis[p]) {
			vis[p] = 1;
			if (!match[p] || dfs(match[p])) {
				match[p] = x;
				return 1;
			}
		}
	}
	return 0;
}

int main() {
	scanf("%d", &t);
	while (t--) {
		scanf("%d", &n);
		for (int i = 1; i <= n; i++) {
			G[i].clear();
			match[i] = 0;
		}
		
		for (int i = 1; i <= n; i++) {
			for (int j = 1; j <= n; j++) {
				int x;
				scanf("%d", &x);
				if (x) {
					add(i, j);
				}
			}
		}
		int ans = 0;
		for (int i = 1; i <= n; i++) {
			memset(vis, 0, sizeof(vis));
			if (dfs(i)) ans++;
		}
		if (ans == n) {
			printf("Yes
");
		}
		else {
			printf("No
");
		}
	}
	return 0;
}