Cod sursa(job #654926)

Utilizator bia.liliPoenar Liana bia.lili Data 31 decembrie 2011 12:46:38
Problema Fractii Scor 0
Compilator c Status done
Runda Arhiva de probleme Marime 0.3 kb
Raporteaza aceasta sursa 
# include <iostream.h>
# include <fstream.h>
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;
}