Cod sursa(job #3165053)

Utilizator Alexbora13Bora Ioan Alexandru Alexbora13 Data 5 noiembrie 2023 12:41:36
Problema Numarare triunghiuri Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.82 kb
#include <bits/stdc++.h>
#define START ios::sync_with_stdio(false); fin.tie(NULL); fout.tie(NULL);
#define STOP fin.close(); fout.close(); return 0;
using namespace std;

ifstream fin("nrtri.in");
ofstream fout("nrtri.out");

int n, rez, x;
vector <int> v;

int CB(int i, int j)
{
    int st = 1, dr=n-1;
    while(st<=dr)
    {
        int mij = (st+dr)/2;
        if(v[mij]<=v[i]+v[j])
            st=mij+1;
        else
            dr=mij-1;
    }
    return dr;
}

int main()
{
    START
    fin >> n;
    for(int i=0; i<n; i++)
    {
        fin >> x;
        v.push_back(x);
    }
    sort(v.begin(),v.end());
    for(int i=0; i<n; i++)
        cout << v[i] << ' ';
    cout << '\n';
    for(int i=0; i<n; i++)
    {
        for(int j=i+1; j<n; j++)
        {
            rez+=CB(i,j)-j;
        }
    }
    fout << rez;
    STOP
}