Cod sursa(job #2665190)
Utilizator | Alex Girleanu alex.girleanu | Data | 30 octombrie 2020 12:39:38 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.62 kb |
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int v[1003],n,s,nr,i,j;
int st,dr,mid;
int main()
{
fin>>n;
for(i=1;i<=n;i++)
fin>>v[i];
sort(v+1,v+n+1);
for(i=1;i<=n-2;i++)
for(j=i+1;j<=n-1;j++){
s=v[i]+v[j];
st=j+1;
dr=n;
while(st<=dr){
mid=(st+dr)/2;
if(v[mid]>s)
dr=mid-1;
else
st=mid+1;
}
nr=nr+dr-j;
}
fout<<nr;
return 0;
}