poj-1469-COURSES-二分图匹配-匈牙利算法（模板）

 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 }