【bzoj1854】 SCOI2010游戏 二分图匹配

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<iostream>
#include<algorithm>
#define maxn 10010
#define maxm 1000010

using namespace std;

int head[maxm],next[2*maxm],to[2*maxm];
int lk[maxm],vis[maxm];
int n,m,T,num,ans;

void addedge(int x,int y)
{
	num++;to[num]=y;next[num]=head[x];head[x]=num;
}

bool find(int x)
{
	for (int p=head[x];p;p=next[p])
	  if (vis[to[p]]!=T)
	  {
	  	vis[to[p]]=T;
	  	if (!lk[to[p]] || find(lk[to[p]]))
	  	{
	  		lk[to[p]]=x;
	  		return 1;
	  	}
	  }
	return 0;
}

int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;i++)
	{
		int x,y;
		scanf("%d%d",&x,&y);
		addedge(x,i);addedge(y,i);
	}
	for (int i=1;i<=10000;i++)
	{
		T++;
		if (find(i)) ans++;
		else break;
	}
	printf("%d\n",ans);
	return 0;
}