Cod sursa(job #59895)
Utilizator | Bozianu Ana anna_bozianu | Data | 11 mai 2007 04:07:32 |
---|---|---|---|
Problema | Medie | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.4 kb |
#include<stdio.h>
long long int n,i,j,a,c[7001],sol;
int main()
{
FILE *f,*g;
f=fopen("medie.in","r");
g=fopen("medie.out","w");
fscanf(f,"%lld",&n);
for(i=1;i<=n;i++)
{fscanf(f,"%lld",&a);c[a]++;}
for(i=1;i<=6998;i++)
if(c[i])
{ sol+=c[i]*(c[i]-1)*(c[i]-1);
for(j=i+1;2*j<=i+7000;j++)
sol+=c[i]*c[j]*c[2*j-i];
}
sol/=2;
fprintf(g,"%lld\n",sol);
fcloseall();
return 0;
}