Cod sursa(job #425809)
Utilizator | Stoianovici Horatiu Andrei horeste12 | Data | 26 martie 2010 09:41:28 |
---|---|---|---|
Problema | Medie | Scor | 60 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.5 kb |
#include<cstdio>
#include<fstream>
using namespace std;
FILE *f;
ofstream g("medie.out");
int n,a[10001],v[10001],frecv[10001],i,j;
long long nr;
int main()
{
f=fopen("medie.in","r");
fscanf(f,"%d\n",&n);
for(i=1;i<=n;i++)
{
fscanf(f,"%d\n",&a[i]);frecv[a[i]]++;
}
for(i=1;i<n;i++)
for(j=i+1;j<=n;j++)
if(((a[j]+a[i])&1)==0)
{
int x=(a[j]+a[i])>>1;
v[x]++;
nr+=frecv[x];
if(a[i]==x)
nr-=2;
}
g<<nr<<'\n';
fclose(f);
g.close();
return 0;
}