2
3 3
3 1 2 3
2 1 2
1 1
3 3
2 1 3
2 1 3
1 1

YES
NO

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我的解答:

不清楚每个学生是不是一定要分到课,只考虑每个课都得分到学生,过了.二分图,匈牙利算法.

/*=============================================================================
#     FileName: 1469.cpp
#         Desc: poj 1469
#       Author: zhuting
#        Email: cnjs.zhuting@gmail.com
#     HomePage: my.oschina.net/locusxt
#      Version: 0.0.1
#    CreatTime: 2013-12-07 18:21:46
#   LastChange: 2013-12-07 18:21:46
#      History:
=============================================================================*/
#include <cstdio>
#include <cstdlib>
#include <string>
#include <cstring>
#include <algorithm>
#define maxp 105 /*courses*/
#define maxn 305 /*student*/bool mymap[maxp][maxn] = {0};
bool cover[maxn] = {0};
int link_[maxn] = {0};
int n = 0, p = 0;/*p = course_num, n = student_num*/bool find(int x)
{for (int i = 0; i < n; ++i){if (!cover[i] && mymap[x][i]){cover[i] = 1;if (link_[i] == -1 || find(link_[i])){link_[i] = x;return 1;}}}return 0;
}void init()
{memset(mymap, 0, sizeof(mymap));memset(cover, 0, sizeof(cover));memset(link_, 0xff, sizeof(link_));return;
}int main()
{int t = 0;int link__num = 0;int tmp = 0;scanf("%d", &t);while(t--){int ans = 0;init();scanf("%d%d", &p, &n);for(int i = 0; i < p; ++i){scanf("%d", &link__num);for (int j = 0; j < link__num; ++j){scanf("%d", &tmp);mymap[i][tmp - 1] = 1;}}for (int i = 0; i < p; ++i){memset(cover, 0, sizeof(cover));if (find(i)) ++ans;}//printf("%d\n", ans);if (ans == p) printf("YES\n");else printf("NO\n");}return 0;
}