Cod sursa(job #1788755)
Utilizator | Data | 26 octombrie 2016 13:34:37 | |
---|---|---|---|
Problema | Medie | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.61 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("medie.in");
ofstream g("medie.out");
bool cmp(int x, int y)
{
return x>=y;
}
//int ceva(int x)
//a+b =2*c
int main()
{
int n, rez=0;
f>>n;
vector<int> a(n);
vector<int> frecvente(15000,0);
for(int i=0; i<n; ++i)
{
f>>a[i];
frecvente[a[i]*2]++;
}
//sort(a.begin(),a.end(),cmp);
for(int i=0; i<n; ++i)
{
for(int j=i+1; j<n; ++j)
{
rez+=frecvente[a[i]+a[j]];
if(a[i]==a[j]) rez-=2;
}
}
g<<rez;
return 0;
}