Cod sursa(job #1798449)

Utilizator BlueCodeMihalache Catalin Alexandru BlueCode Data 5 noiembrie 2016 11:09:37
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;

 ifstream f("fractii.in");
 ofstream g("fractii.out");
int v[1000005];
int i,j,n;
long long nr=0;

int main()
{
    f>>n;
    for(i=1;i<=n;i++)
        v[i]=i-1;
    for(i=2;i<=n;i++)
        {for(j=i*2;j<=n;j+=i)
        v[j]-=v[i];
            nr+=v[i];}

   g<<2*nr+1;


}