poj 1274 The Perfect Stall （匈牙利算法）

 1#include <cstdio>
 2#include <cstring>
 3#include <iostream>
 4#include <algorithm>
 5#include <vector>
 6#include <queue>
 7#include <set>
 8#include <map>
 9#include <string>
10#include <cmath>
11#include <cstdlib>
12#include <ctime>
13#define fst first
14#define sec second
15#define lson l,m,rt<<1
16#define rson m+1,r,rt<<1|1
17#define ms(a,x) memset(a,x,sizeof(a))
18typedef long long LL;
19#define pi pair < int ,int >
20#define MP make_pair

 1using namespace std;
 2const double eps = 1E-8;
 3const int dx4[4]={1,0,0,-1};
 4const int dy4[4]={0,-1,1,0};
 5const int inf = 0x3f3f3f3f;
 6const int N=405;
 7int n,m;
 8int head[N];
 9int cnt;
10int link[N];
11bool vis[N];
12struct Edge
13{
14    int v;
15    int nxt;
16}edge[N*N];
17void addedge(int u,int v)
18{
19    edge[cnt].v = v;
20    edge[cnt].nxt = head[u];
21    head[u] = cnt;
22    cnt++;
23}

1bool dfs( int u)
2{
3  //  cout<<"u:"<<u<<endl;
4    for ( int i = head[u] ; i!=-1 ; i = edge[i].nxt)
5    {
6	int v = edge[i].v;
7//	cout<<"v:"<<v<<endl;
8	if (vis[v]) continue;
9	vis[v] = true;

 1	if (link[v]==-1||dfs(link[v]))
 2	{
 3	    link[v] = u;
 4	    return true;
 5	}
 6    }
 7    return false;
 8}
 9int hung()
10{
11    int res = 0 ;
12    ms(link,-1);
13    for ( int i = 1 ; i <= n ; i++)
14    {
15	ms(vis,false);
16	if (dfs(i)) res++;
17    }

1    return res;
2}
3int main()
4{
5	#ifndef  ONLINE_JUDGE 
6	freopen("code/in.txt","r",stdin);
7  #endif

1	while (scanf("%d%d",&n,&m)!=EOF)
2	{
3	    ms(head,-1);
4	    cnt = 0 ;

 1	    for ( int i = 1 ; i <= n ; i++)
 2	    {
 3		int num;
 4		scanf("%d",&num);
 5		while (num--)
 6		{
 7		    int x;
 8		    scanf("%d",&x);
 9		    x = x + n;
10		    addedge(i,x);
11		}
12	    }
13	    int ans = hung();
14	    printf("%d\n",ans);
15	}

1  #ifndef ONLINE_JUDGE  
2  fclose(stdin);
3  #endif
4    return 0;
5}