Cod sursa(job #1048968)

Utilizator ValeraShulghin Valera Valera Data 6 decembrie 2013 17:55:44
Problema Fractii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");

int main()
{
    int a[1000000],n,i,j,s;
    f>>n;
    for (i=2;i<=n;i++)
        a[i]=i-1;

    for (i=2;i<=n;i++)
    {
        s+=a[i];
        for (j=2*i;i<=n;j+=i)
            a[j]-=a[i];
    }
    s=2*s+1;
    g<<s;
    return 0;
}