#include<iostream>
using namespace std;
const int maxn = 201;
const int maxm = 201;

struct gtype
{
	int x, y, next;
};
gtype g[maxm];
int first[maxn];
int link[maxn];
bool used[maxn];
int n, m, tot;

void add(int x, int y)
{
	tot++;
	g[tot].x = x;
	g[tot].y = y;
	g[tot].next = first[x];
	first[x] = tot;
}
bool find(int s)
{
	int temp;
	temp = first[s];
	while(temp != -1)
	{
		if( !used[g[temp].y])
		{
			used[g[temp].y] = true;
			if(link[g[temp].y]==0 || find(link[g[temp].y]))
			{
				link[g[temp].y] = s;
				return true;
			}
		}
		temp = g[temp].next;
	}
	return false;
}
int main()
{
	int i, j, k, x, y;
	int ans;
	while(cin>>n>>m)
	{
		for(x=1; x<=n; x++)
		{
			cin>>k;
			for(j=1; j<=k; j++)
			{
				cin>>y;
				add(x, y);
			}
		}
		memset(link, 0, sizeof(link));
		for(i=1; i<=n; i++)
		{
			memset(used, false, sizeof(used));
			find(i);
		}
		ans = 0;
		for(i=1; i<=n; i++)
		{
			if(link[i] != 0)
			{
				ans++;
				//cout<<link[i]<<" "<<i<<endl;
			}
		}
		//printf("%d\n",ans);
		cout<<ans<<endl;
	}
	return 0;
}

• 上面是用链表写的超时，怎么会这么慢呢？？下面是用矩阵写的AC， (1066) zsc08_wangqiang 2010-08-24 20:42:50