Cod sursa(job #2767276)
Utilizator | Darius Covaciu dcov | Data | 5 august 2021 14:50:34 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.87 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("nrtri.in");
ofstream g("nrtri.out");
int main()
{
int n,a[801],nr=0;
f>>n;
for(int i=0;i<n;i++)
f>>a[i];
int ok=1;
while(ok)
{
ok=0;
for(int i=0;i<n-1;i++)
{
if(a[i]>a[i+1])
{
int aux=a[i];
a[i]=a[i+1];
a[i+1]=aux;
ok=1;
}
}
}
for(int i=0;i<n-1;i++)
{
for(int j=i+1;j<n;j++)
{
int s=a[i]+a[j],lg=1;
for(lg=1;lg<=n;lg<<=1);
int k;
for(k=j;lg!=0;lg>>=1)
{
if(k+lg<n && a[k+lg]<=s)
k+=lg;
}
nr+=k-j;
}
}
g<<nr;
return 0;
}