hdu 2063 过山车

#include <cstring>
#include <cstdio>
#define N 505

bool vis[N];
int ans,Map[N][N],match[N],k,m,n;

int dfs(int x)
{
    for(int i=1;i<=n;++i)
    {
        if(Map[x][i]&&!vis[i])
        {
            vis[i]=1;
            if(!match[i]||dfs(match[i]))
            {
                match[i]=x;
                return 1;
            }
        }
    }
    return 0;
}
int main()
{
    for(;scanf("%d",&k)&&k;)
    {
        scanf("%d%d",&m,&n);
        memset(Map,0,sizeof(Map));
        memset(match,0,sizeof(match));
        ans=0;
        for(int x,y;k--;)
        {
            scanf("%d%d",&x,&y);
            Map[x][y]=1;
        }
        for(int i=1;i<=m;++i)
        {
            memset(vis,0,sizeof(vis));
            ans+=dfs(i);
        }
        printf("%d\n",ans);
    }
    return 0;
}