Cod sursa(job #1577204)

Utilizator Mihai9Oniga Mihai Mihai9 Data 23 ianuarie 2016 12:22:42
Problema Fractii Scor 90
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.27 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;ifstream fin("fractii.in");ofstream fout("fractii.out");long long nr=1LL,n, a[1000005];int main (){fin>>n;for (int i=1;i<=n;i++){a[i]=i-1;}for (int i=1;i<=n;i++){nr+=a[i];for (int j=2*i;j<=n;j+=i)a[j]-=a[i];}nr=nr*2;fout<<--nr;return 0;}