BNUOJ 1541 Air Raid

 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 #include <stack>
13 #define LL long long
14 #define pii pair<int,int>
15 #define INF 0x3f3f3f3f
16 using namespace std;
17 const int maxn = 200;
18 int mp[maxn][maxn],from[maxn],n,m;
19 bool vis[maxn];
20 bool dfs(int u){
21     for(int v = 1; v <= n; v++){
22         if(mp[u][v] && !vis[v]){
23             vis[v] = true;
24             if(from[v] == -1 || dfs(from[v])){
25                 from[v] = u;
26                 return true;
27             }
28         }
29     }
30     return false;
31 }
32 int main() {
33     int t,u,v,ans,i;
34     scanf("%d",&t);
35     while(t--){
36         scanf("%d %d",&n,&m);
37         memset(mp,0,sizeof(mp));
38         memset(from,-1,sizeof(from));
39         for(i = 0; i < m; i++){
40             scanf("%d %d",&u,&v);
41             mp[u][v] = 1;
42         }
43         ans = 0;
44         for(i = 1; i <= n; i++){
45             memset(vis,false,sizeof(vis));
46             if(dfs(i)) ans++;
47         }
48         printf("%d\n",n-ans);
49     }
50     return 0;
51 }