Cod sursa(job #1741221)
Utilizator | Data | 13 august 2016 13:00:27 | |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.66 kb |
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int n,i,st,dr,mid,s,nr,a[802],j;
int main()
{
fin >> n;
for (i=1;i<=n;i++)
fin >> a[i];
sort (a+1,a+n+1);
for (i=1;i<=n-2;i++){
for (j=i+1;j<=n-1;j++){
s=a[i]+a[j];
st=j+1;
dr=n;
while (st<=dr){
mid=(st+dr)/2;
if (s<a[mid])
dr=mid-1;
else
break;
}
if (s>=a[mid])
nr++;
}
}
fout << nr;
return 0;
}