匈牙利算法

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1005;
const int mod= 1e9+7;
#define ll long long
int n,m,e,u,v;
int match[maxn],vised[maxn];
vector<int> g[maxn];
bool dfs(int u,int tag){
    if(vised[u] == tag) return false;
    vised[u] = tag;
    for(auto v :g[u]){
        if(match[v] ==0 || dfs(match[v],tag)) {
            match [v] = u;
            return true;
        }
    }
    return false ;
}
int main() {
    scanf("%d%d%d",&n,&m,&e);
    for(int i=1;i<=e;i++){
        scanf("%d%d",&u,&v);
        g[u].push_back(v);
    }
    int ans=0;
    for(int i=1;i<=n;i++) {
        if(dfs(i,i))ans++;
    }
    printf("%d\n",ans);

    return 0 ;
}