Cod sursa(job #2154629)

Utilizator MDiana15Diana M MDiana15 Data 7 martie 2018 09:43:24
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.31 kb
Raporteaza aceasta sursa 
#include <fstream>

using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int n,d,p,i,a[1000006],j;
long long s;
int main()
{
   f>>n;
   for(i=2;i<=n;i++)a[i]=i-1;
   for(i=2;i<=n;i++)
   {
    s=s+a[i];
    for(j=2*i;j<=n;j=j+i)a[j]=a[j]-a[i];
   }
   g<<s*2+1;
    return 0;
}