hdu 1083 Courses(二分图 )

#include<stdio.h>
#define N 1000
#include<string.h>
int result[N],map[N][N],vis[N],n,m;
int dfs(int x)
{
    int i;
    for(i=1;i<=m;i++)
    {
        if(!vis[i]&&map[x][i])
        {
            vis[i]=1;
            if(result[i]==0||dfs(result[i]))
            {
                result[i]=x;
                return 1;
            }
        }
    }
    return 0;

}
int main()
{
    int l,i,num,b;
    scanf("%d",&l);
    while(l--)
    {
        scanf("%d%d",&n,&m);
        memset(result,0,sizeof(result));
        memset(map,0,sizeof(map));
        //if(n!=m){printf("NO\n");continue;}
        for(i=1;i<=n;i++)
        {
            scanf("%d",&num);
            while(num--)
            {
                scanf("%d",&b);
                map[i][b]=1;

            }
        }
        int ans=0;
       for(i=1;i<=n;i++)
       {
           memset(vis,0,sizeof(vis));
           if(dfs(i))ans++;
       }
       if(ans==n)printf("YES\n");
       else printf("NO\n");
    }
}