Cod sursa(job #2982422)
Utilizator | Preppy Girl Jungwon | Data | 20 februarie 2023 11:54:03 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.66 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("nrtri.in");
ofstream g("nrtri.out");
int cb(int st, int dr, int v[], int s)
{
int k=0,mj=0,poz=0,j=st-1;
while(st<=dr)
{
mj=(st+dr)/2;
if(v[mj]<=s)
poz=mj,st=mj+1;
else
dr=mj-1;
}
if(poz)
return poz-j;
return 0;
}
int n,s,v[100001],k;
int main()
{
f>>n;
for(int i=1;i<=n;i++)
f>>v[i];
sort(v+1,v+n+1);
for(int i=1;i<n;i++)
{
for(int j=i+1;j<=n;j++)
{
s=v[i]+v[j];
k=k+cb(j+1,n,v,s);
}
}
g<<k;
return 0;
}