Cod sursa(job #2061811)

Utilizator stahlhelmVirtejaru Mihai stahlhelm Data 9 noiembrie 2017 18:48:31
Problema Fractii Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.33 kb
Raporteaza aceasta sursa 
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream c("fractii.out");
int main()
{ int s=1,v[100000],N,i,j;
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=j+i)
        v[j]=v[j]-v[i];

 for(i=1;i<=N;++i)
    s=s+2*v[i];
c<<s;
return 0;
}