Cod sursa(job #2381801)
Utilizator | Andries Vlad Andrei vladad | Data | 17 martie 2019 13:24:28 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.62 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("nrtri.in");
ofstream g("nrtri.out");
int n, st, dr, mij, v[1001], t, u;
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++)
{
t=v[i]+v[j];
st=j+1;
dr=n;
while(st<=dr)
{
mij=(st+dr)/2;
if(t<v[mij]) dr=mij-1;
else
st=mij+1;
}
u=u+dr-j;
}
}
g<<u;
return 0;
}