【二分图+最大匹配】北大 poj 1274 The Perfect Stall

 

/* THE PROGRAM IS MADE BY PYY */
/*----------------------------------------------------------------------------//
	Copyright (c) 2011 panyanyany All rights reserved.

	URL   : http://poj.org/problem?id=1274
	Name  : 1274 The Perfect Stall

	Date  : Tuesday, December 20, 2011
	Time Stage : half an hour

	Result: 
9673709	panyanyany
1274
Accepted	324K	0MS	C++
1216B	2011-12-20 21:19:16

Test Data :

Review :
水题……
//----------------------------------------------------------------------------*/

#include <stdio.h>
#include <string.h>

#define MAXSIZE	202

int		n, m ;
int		link[MAXSIZE] ;
bool	cover[MAXSIZE] ;
int		graph[MAXSIZE][MAXSIZE] ;

bool find (int cur)
{
	int i, j ;
	for (i = 1 ; i <= graph[cur][0] ; ++i)
	{
		j = graph[cur][i] ;
		if (cover[j] == false)
		{
			cover[j] = true ;
			if (!link[j] || find (link[j]))
			{
				link[j] = cur ;
				return true ;
			}
		}
	}
	return false ;
}

int main (void)
{
	int i, j ;
	int sum ;

	while (~scanf ("%d%d", &n, &m))
	{
		for (i = 1 ; i <= n ; ++i)
		{
			scanf ("%d", &graph[i][0]) ;
			for (j = 1 ; j <= graph[i][0] ; ++j)
				scanf ("%d", &graph[i][j]) ;
		}

		sum = 0 ;
		memset (link, 0, sizeof (link)) ;
		for (i = 1 ; i <= n ; ++i)
		{
			memset (cover, 0, sizeof (cover)) ;
			sum += find (i) ;
		}

		printf ("%d\n", sum) ;
	}
	return 0 ;
}