Cod sursa(job #425795)
Utilizator | Data | 26 martie 2010 09:24:07 | |
---|---|---|---|
Problema | Medie | Scor | 60 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.52 kb |
#include<cstdio>
#include<fstream>
using namespace std;
FILE *f;
ofstream g("medie.out");
int n,a[10001],v[10001],frecv[10001],i,j,k;
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]);
for(i=1;i<n;i++)
{
frecv[a[i]]++;
for(j=i+1;j<=n;j++)
if(((a[j]+a[i])&1)==0)
v[(a[j]+a[i])>>1]++;
}
frecv[a[n]]++;
for(i=1;i<=7001;i++)
if(v[a[i]])
{ nr+=v[a[i]]-frecv[a[i]]+1;}
g<<nr<<'\n';
fclose(f);
g.close();
return 0;
}