Cod sursa(job #654923)

Utilizator bia.liliPoenar Liana bia.lili Data 31 decembrie 2011 12:39:32
Problema Fractii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
# include <fstream>
usingnamespace std;
int main()
   ifstream f("fractii.in");
   ofstream g("fractii.out");
   int main()
   {
       long long k,n,x[1000001],i,m=0;
       f>>n;
    f.close();
    for(i=2;i<=n;i++)
    x[i]=i-1;
   for(i=2;i<=n;i++)
{
m+=x[i];
for(k=2*i;k<=n;k+=i)
x[k]-=x[i];
  }
   g<<m*2+1;
g.close();
return 0;
}