ASC1 D Matrix Multiplication

 1 // File Name: a.cpp
 2 // Author: darkdream
 3 // Created Time: 2015年03月21日 星期六 14时05分54秒
 4 
 5 #include<vector>
 6 #include<list>
 7 #include<map>
 8 #include<set>
 9 #include<deque>
10 #include<stack>
11 #include<bitset>
12 #include<algorithm>
13 #include<functional>
14 #include<numeric>
15 #include<utility>
16 #include<sstream>
17 #include<iostream>
18 #include<iomanip>
19 #include<cstdio>
20 #include<cmath>
21 #include<cstdlib>
22 #include<cstring>
23 #include<ctime>
24 #define LL long long
25 
26 using namespace std;
27 int n , m;
28 int sum[10005];
29 int main(){
30      freopen("matrix.in","r",stdin);
31      freopen("matrix.out","w",stdout);
32      scanf("%d %d",&n,&m);
33      int ta,tb;
34      for(int i = 1;i <= m;i ++)
35      {
36            scanf("%d %d",&ta,&tb);;
37            sum[ta]++;
38            sum[tb]++;
39      }
40      LL ans = 0 ; 
41      for(int i= 1;i <= n;i ++)
42      {
43          ans += sum[i]*sum[i];
44      }
45      printf("%I64d\n",ans);
46 return 0;
47 }