Cod sursa(job #1865501)

Utilizator gumitza68Marsky7 gumitza68 Data 1 februarie 2017 19:50:52
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
ifstream cin("fractii.in");
ofstream cout("fractii.out");
int n,i,j,v[1000001];
long long x;
int main()
{
    cin>>n;
    for(i=1;i<=n;i++)
    {
        v[i]=v[i]+i-1;
        x=x+(long long)(2*v[i]);
        for(j=2*i;j<=n;j+=i)
            v[j]=v[j]-v[i];
    }
    cout<<x+1;
    return 0;
}