Cod sursa(job #1703732)
Utilizator | Pincu Catalin pincucatalin | Data | 17 mai 2016 16:01:30 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 95 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.61 kb |
#include <cstdio>
#include <algorithm>
using namespace std;
FILE *in=fopen ("nrtri.in","r");
FILE *out=fopen ("nrtri.out","w");
int n, v[800],nr;
int main()
{
fscanf (in,"%d",&n);
for (int i=1;i<=n;i++)
fscanf (in,"%d",&v[i]);
sort (v+1,v+1+n);
for (int i=1;i<n-1;i++)
for (int j=i+1;j<n;j++)
{
int k=j,pas=1<<10;
while (pas!=0)
{
if (k+pas<=n && v[k+pas]<=v[i]+v[j])
k+=pas;
pas/=2;
}
if (k>j)
nr+=(k-j);
}
fprintf (out,"%d",nr);
return 0;
}