NYOJ 237 游戏高手的烦恼

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <algorithm>
 6 #include <climits>
 7 #include <vector>
 8 #include <queue>
 9 #include <cstdlib>
10 #include <string>
11 #include <set>
12 #define LL long long
13 #define INF 0x3f3f3f3f
14 using namespace std;
15 const int maxn = 510;
16 int n,llink[maxn<<1];
17 vector<int>g[maxn<<1];
18 bool used[maxn<<1];
19 bool dfs(int u) {
20     for(int v = 0; v < g[u].size(); v++) {
21         if(!used[g[u][v]]) {
22             used[g[u][v]] = true;
23             if(llink[g[u][v]] == -1 || dfs(llink[g[u][v]])) {
24                 llink[g[u][v]] = u;
25                 return true;
26             }
27         }
28     }
29     return false;
30 }
31 int main() {
32     int t,i,j,m,u,v;
33     scanf("%d",&t);
34     while(t--) {
35         scanf("%d%d",&n,&m);
36         j = n<<1;
37         for(i = 0; i <= j; i++) {
38             g[i].clear();
39         }
40         while(m--) {
41             scanf("%d%d",&u,&v);
42             g[u].push_back(n+v);
43         }
44         memset(llink,-1,sizeof(llink));
45         int ans = 0;
46         n <<= 1;
47         for(i = 1; i <= n; i++) {
48             memset(used,false,sizeof(used));
49             if(dfs(i)) ans++;
50         }
51         printf("%d\n",ans);
52     }
53     return 0;
54 }