POJ1274(匈牙利算法)

找二分圖最大匹配

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <queue>
#include <cstring>
using namespace std;

int edge[205][205];
int used[205];
int belong[205];
int n,m;
bool findpath(int x)
{
	int i;
	for (i=1;i<=m;i++)
	{
		if (edge[x][i] && !used[i])
		{
			used[i]=1;
			//當一個節點沒有被佔用 或者 佔用該節點的節點可以“挪動”指向其它節點
			if (belong[i]==0 || findpath(belong[i]) )
			{
				belong[i]=x;
				return true;
			}
		}
	}
	return false;
}

int main()
{
	int i,j;
	while (scanf("%d",&n)!=EOF)
	{
		memset(belong,0,sizeof(belong));
		memset(edge,0,sizeof(edge));
		scanf("%d",&m);
		for (i=1;i<=n;i++)
		{
			int x;
			scanf("%d",&x);
			for (j=0;j<x;j++)
			{
				int y;
				scanf("%d",&y);
				edge[i][y]=1;
			}
		}
		int ans=0;
		for (i=1;i<=n;i++)
		{
			memset(used,0,sizeof(used));
			if (findpath(i))
				ans++;
		}
		printf("%d\n",ans);
	}
}