Cod sursa(job #3153795)
Utilizator | Costin marcandreicostin | Data | 1 octombrie 2023 12:38:17 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.6 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int n,i,a[805],mij,dr,st,j,s;
int main()
{
fin>>n;
for(i=1; i<=n; i++)
fin>>a[i];
sort(a,a+n+1);
for(i=1; i<=n-2; i++)
for(j=i+1; j<=n; j++)
{
st=j+1;
dr=n;
while(st<=dr)
{
mij=(dr+st)/2;
if(a[mij]<=a[i]+a[j])
st=mij+1;
else
dr=mij-1;
}
s=s+dr-j;
}
fout<<s;
return 0;
}