Cod sursa(job #2181087)
Utilizator | Marinescu Ioana ioana_marinescu | Data | 21 martie 2018 13:56:29 |
---|---|---|---|
Problema | Medie | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.5 kb |
#include <bits/stdc++.h>
const int MAX_N = 9005;
const int MAX_VAL = 7005;
using namespace std;
ifstream fin("medie.in");
ofstream fout("medie.out");
int n, v[MAX_N], vf[MAX_VAL], s[2*MAX_VAL], sol;
int main()
{
int i, j;
fin>>n;
for(i=1; i<=n; i++) {
fin>>v[i];
vf[v[i]]++;
}
for(i=1; i<n; i++)
for(j=i+1; j<=n; j++)
s[v[i]+v[j]]++;
for(i=1; i<=n; i++)
sol+=s[2*v[i]]-(vf[v[i]]-1);
fout<<sol<<'\n';
return 0;
}