Cod sursa(job #2070419)

Utilizator Darie.FlaviusDarie Flavius Darie.Flavius Data 19 noiembrie 2017 15:38:38
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.34 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream c("fractii.out");
int main()
{
int n,v[1000001],i,j;
long long s=1;
f>>n;
  for (i=1;i<=n;i++)
    v[i]=i-1;
for (i=2;i<=n;i++)
   for (j=2*i;j<=n;j+=i)
        v[j]=v[j]-v[i];
 for(i=1;i<=n;i++)
    s+=2*v[i];
c<<s;
return 0;
}