luogu_3386 【模板】二分图匹配

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
#include <cstring>
using namespace std;
const int N=1010;
int n,m,link[N],e;
bool vis[N];
vector<int> G[N];

bool can(int u){
	for(int i=0;i<G[u].size();i++){
		int v=G[u][i];
		if(!vis[v]){
			vis[v]=1;
			if(link[v]==-1 || can(link[v])){
				link[v]=u;
				return 1;
			}
		}
	}
	return 0;
}

int main(){
	scanf("%d%d%d",&n,&m,&e);
	while(e--){
		int u,v;
		scanf("%d%d",&u,&v);
		if(v<=m && u<=n)G[u].push_back(v);
	}
	int sum=0;
	memset(link,0xff,sizeof(link));
	for(int i=1;i<=n;i++){
		memset(vis,0,sizeof(vis));
		if(can(i))sum++;
	}
	printf("%d\n",sum);
	return 0;
}