HDU 1704 Rank

 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 = 510;
18 int n,m;
19 bool mp[maxn][maxn];
20 void Floyd(){
21     for(int k = 1; k <= n; k++){
22         for(int i = 1; i <= n; i++){
23             for(int j = 1; mp[i][k]&&j <= n; j++)
24                 mp[i][j] |= mp[i][k]&mp[k][j];
25         }
26     }
27 }
28 int main() {
29     int t,u,v,ans;
30     scanf("%d",&t);
31     while(t--){
32         scanf("%d %d",&n,&m);
33         memset(mp,false,sizeof(mp));
34         for(int i = 0; i < m; i++){
35             scanf("%d %d",&u,&v);
36             mp[u][v] = true;
37         }
38         Floyd();
39         ans = 0;
40         for(int i = 1; i <= n; i++){
41             for(int j = i+1; j <= n; j++)
42                 if(mp[i][j] == 0 && mp[j][i] == 0) ans++;
43         }
44         printf("%d\n",ans);
45     }
46     return 0;
47 }