Cod sursa(job #2664953)
Utilizator | Dobrin Cotea Antonio Dobrin_Antonio | Data | 29 octombrie 2020 19:47:51 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.6 kb |
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int v[801],n,S;
int main()
{
fin>>n;
for (int i=1;i<=n;i++)
fin>>v[i];
sort(v+1,v+n+1);
for (int i=1;i<=n-2;i++)
for (int j=i+1;j<=n-1;j++){
int s=v[i]+v[j];
int st=j+1,dr=n;
while (st<=dr){
int mid=(st+dr)/2;
if (v[mid]>s)
dr=mid-1;
else
st=mid+1;
}
S=S+dr-j;
}
fout<<S;
return 0;
}