Cod sursa(job #2200627)

Utilizator gagasergiugaga sergiu gagasergiu Data 2 mai 2018 00:07:50
Problema Fractii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.32 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int n,nr,i,j,v[1000001];
int main()
{   cin>>n;
    for(i=1;i<=n;i++)v[i]=i;
    for(i=1;i<=n;i++)
    {
        nr+=v[i];

        for(j=i+i;j<=n;j+=i)
        v[j]-=v[i];}
    cout<<2*nr-1;



}