1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <vector> 5 using namespace std; 6 const int maxn = 555; 7 int n, p; 8 vector<int> g[maxn]; 9 int from[maxn], tot;10 bool use[maxn];11 12 bool match(int x)13 {14    for (int i = 0; i < g[x].size(); i ++) {15       if(!use[g[x][i]]) {16          use[g[x][i]] = true;17          if(from[g[x][i]] == -1 || match(from[g[x][i]])) {18             from[g[x][i]] = x;19             return true;20          }21       }22    }23    return false;24 }25 26 int hungary()27 {28    tot = 0;29    memset(from, -1, sizeof(from));30    for(int i = 1; i <= n; i ++) {31       memset(use, 0, sizeof(use));32       if(match(i)) tot ++;33    }34    return tot;35 }36 37 int main()38 {39    int t; cin>>t;40    while(t--) {41       for(int i = 0; i < maxn; i++) g[i].clear();42       scanf("%d%d", &p, &n);43       for(int i = 1; i <= p; i++) {44          int k; scanf("%d", &k);45          for(int j = 0; j < k; j++) {46             int a; scanf("%d", &a);47             g[i].push_back(a);48          }49       }50       int res = hungary();51       //cout<<res<<endl;52       if(res == p) printf("YES\n");53       else printf("NO\n");54    }55 }