Cod sursa(job #3141258)
Utilizator | Bucovan Mihnea ingineur-mih | Data | 13 iulie 2023 13:44:53 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.72 kb |
#include <iostream>
#include <algorithm>
using namespace std;
const int NMAX=801;
int a[NMAX];
int main() {
freopen("nrtri.in", "r", stdin);
freopen("nrtri.out", "w", stdout);
int n,nr=0;
cin>>n;
for(int i=1;i<=n;i++)
cin>>a[i];
sort(a+1, a+n+1);
for(int i=1;i<=n-1;i++)
for(int j=i+1;j<=n;j++)
{
int st = j, dr = n, poz = j;
while(st <= dr)
{
int m = (st + dr) / 2;
if(a[m] <= a[i] + a[j])
{
st = m + 1;
poz = m;
}
else
dr = m - 1;
}
nr+=poz-j;
}
cout<<nr;
return 0;
}