Cod sursa(job #3229163)
Utilizator | cezara dobrescu _cezara._14 | Data | 14 mai 2024 09:49:44 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 5 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.87 kb |
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int v[3001];
int main()
{
int N;
fin>>N;
for(int i=1; i<=N; i++){
fin>>v[i];
}
sort(v+1, v+N+1);
int cnt=0, aux=0;
for(int i=1; i<=N-2; i++)
{
for(int j=1+i; j<=N-1; j++)
{
int st=j+1;
int dr=N;
while(st<=dr){
int mij=(st+dr)/2;
if((v[i]+v[j])>=v[mij])
{
aux=mij;
st=mij+1;
}
else
{
dr=mij-1;
}
}
cnt=cnt+aux-j;
}
}
fout<<cnt;
return 0;
}