Poj_1274 The Perfect Stall -二分图裸题

题目：给牛找棚，每个棚只能容一只牛，牛在对应的棚才能产奶，问最多能让几只牛产奶。

/************************************************
Author        :DarkTong
Created Time  :2016/7/31 10:51:05
File Name     :Poj_1274.cpp
*************************************************/

//#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
using namespace std;
const int maxn = 200 + 10;
int w[maxn][maxn], n, m;
int Left[maxn];
bool used[maxn];
bool match(int i)
{
    for(int j=1;j<=n;++j) if(w[j][i]&&!used[j])
    {
        used[j] = true;
        if(!Left[j]||match(Left[j]))
        {
            Left[j] = i;
            return true;
        }
    }
    return false;
}
//返回最大匹配数
int hungary()
{
    int res=0;
    memset(Left, 0, sizeof(Left));
    for(int i=1;i<=m;++i)
    {
        memset(used, 0, sizeof(used));
        if(match(i)) res++;
    }
    return res;
}

int main()
{
    int T, cas=1;
    while(scanf("%d%d", &m, &n)==2)
    {
        memset(w, 0, sizeof(w));
        int t, x;
        for(int i=1;i<=m;++i)
        {
            scanf("%d", &t);
            for(int j=1;j<=t;++j)
            {
                scanf("%d", &x);
                w[x][i]=1;
            }
        }
        printf("%d\n", hungary());
    }

    return 0;
}