Cod sursa(job #3196621)
Utilizator | Vlad Prismareanu Vlad_pris | Data | 24 ianuarie 2024 13:19:50 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.8 kb |
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int main()
{
int n;
int v[805]={0};
fin>>n;
for(int i=1;i<=n;i++)
fin>>v[i];
sort(v+1,v+n+1);
int cnt=0;
for(int i=1;i<=n;i++)
{
for(int j=i+1;j<=n;j++)
{
int st=j,dr=n,ans=j;
while(st<=dr)
{
int med=(st+dr)/2;
if(v[med]<=v[i]+v[j])
{
st=med+1;
ans=med;
}
else
dr=med-1;
}
cnt+=ans-j;
}
}
fout<<cnt;
return 0;
}