[Bzoj1059][ZJOI2007]矩阵游戏(二分图匹配)

题目链接：https://www.lydsy.com/JudgeOnline/problem.php?id=1059

将行与列看成二分图的两个部分，发现交换行和交换列并不影响二分图，例如：

发现交换第一行和第三行不会影响二分图。

然后就随便写写.......

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 205;
int vis[maxn], Link[maxn], Nx, Ny;
int mp[205][205];
bool dfs(int x) {
    for (int i = 1; i <= Nx; i++) {
        if (!vis[i]&&mp[x][i]) {
            vis[i] = 1;
            if (Link[i] == -1 || dfs(Link[i])) {
                Link[i] = x;
                return true;
            }
        }
    }
    return false;
}
bool xyl() {
    int ans = 0;
    memset(Link, -1, sizeof(Link));
    for (int i = 1; i <= Nx; i++) {
        memset(vis, 0, sizeof(vis));
        if (dfs(i))
            ans++;
    }
    return ans >= Nx;
}
int main() {
    int t;
    scanf("%d", &t);
    while (t--) {
        int n, x;
        scanf("%d", &n);
        memset(mp, 0, sizeof(mp));
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                scanf("%d", &x);
                if (x)
                    mp[i][j] = 1;
            }
        }
        Nx = Ny = n;
        if (xyl())
            printf("Yes\n");
        else
            printf("No\n");
    }
    return 0;
}