Cod sursa(job #2724839)

Utilizator RobertAcAcatrinei Robert-Marian RobertAc Data 17 martie 2021 23:19:03
Problema Fractii Scor 10
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.29 kb
Raporteaza aceasta sursa 
#include <bits/stdc++.h>

using namespace std;
ifstream in("fractii.in");
ofstream out("fractii.out");
int main(){
    long int n,fr=0;
    in>>n;
    for(int i=1;i<=n;i++){
        for(int j=i;j<=n;j++){
            if(__gcd(i,j)==1)fr++;
        }
    }
    out<<fr*2-1;

}