题目链接:?id=1469 题意：最大匹配学生与课程数。 解法：ans == 学生数量 YES else NO 代码：
;int n, m, num, k;int p[310][310];int book[310];int match[310];int t;bool vis[310];bool dfs(int u){int i;for (i = 1; i <= m; i++){if (book[i] == 0 && p[u][i] == 1){book[i] = 1;if (match[i] == 0 || dfs(match[i])){match[i] = u;return true;}}}return false;}int main(){scanf(“%d”,&t);while (t–){memset(p, 0, sizeof(p));memset(match, 0, sizeof(match));memset(vis,false,sizeof(vis));scanf(“%d%d”,&n,&m);for (int i = 1; i <= n; i++){scanf(“%d”,&num);for (int j = 1; j <= num; j++){scanf(“%d”,&k);p[i][k] = 1;//p[num][m] = 1;}}int ans = 0;for (int i = 1; i <= n; i++){memset(book, 0, sizeof(book));if (dfs(i))ans++;}if (ans == n) puts(“YES”);else puts(“NO”);}return 0;}
，流转的时光，都成为命途中美丽的点缀，
