Cod sursa(job #3247961)
| Utilizator | Data | 10 octombrie 2024 08:52:27 | |
|---|---|---|---|
| Problema | Triplete | Scor | 0 |
| Compilator | cpp-64 | Status | done |
| Runda | Arhiva de probleme | Marime | 0.58 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin ("triplete.in");
ofstream fout ("triplete.out");
int n,m,a,b;
long long s=0;
bool f[4097][4097];
int v[4097];
long long calccomb(int n, int k){
long long p=1;
for(long long d=n-k+1;d<=n;d++){
p=p*d;
}
p=p/2;
return p;
}
int main()
{
fin>>n>>m;
for(int i=1;i<=m;i++){
fin>>a>>b;
f[a][b]=1;
v[b]++;
}
for(int i=1;i<=n;i++){
if(v[i]>=2){
s=s+calccomb(v[i],2);
}
}
fout<<s;
return 0;
}
