Cod sursa(job #1856700)

Utilizator lucametehauDart Monkey lucametehau Data 25 ianuarie 2017 12:29:07
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.32 kb
Raporteaza aceasta sursa 
#include <fstream>

using namespace std;
ifstream cin("fractii.in");
ofstream cout("fractii.out");
int n,i,j,v[1000005];
long long x;
int main()
{
    cin>>n;
    for(i=1;i<=n;i++)
    {
        v[i]+=i-1;
        x+=(long long)(2*v[i]);
        for(j=2*i;j<=n;j+=i)
            v[j]-=v[i];
    }
    cout<<x+1;
    return 0;
}