二分图最大匹配 匈牙利算法

模板：洛谷p3386

#include<bits/stdc++.h>
using namespace std;
const int N=5e4+10;
int vis[N],match[N];
vector<int> edges[N];
int n,m,e;
bool dfs(int u){for(int &v:edges[u]){if(vis[v])continue;vis[v]=1;if(!match[v]||dfs(match[v])){match[v]=u;return true;}}return false;
}
int main(){cin.tie(nullptr)->sync_with_stdio(false);cin>>n>>m>>e;for(int i=1;i<=e;i++){int u,v;cin>>u>>v;edges[u].push_back(v);}int ans=0;for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){vis[j]=0;}if(dfs(i))ans++;}cout<<ans<<endl;return 0;
}