Cod sursa(job #1197662)

Utilizator sYnceDAlin Cosmin sYnceD Data 13 iunie 2014 09:36:44
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.33 kb
Raporteaza aceasta sursa 

#include<fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");

int i,j,n,t[1000002];
long long k;

int main()
{
f>>n;


for(i=2;i<=n;i++)
        t[i]=i-1;

k=0;
for(i=2;i<=n;i++)
        {
        for(j=i+i;j<=n;j+=i)t[j]-=t[i];
        k+=t[i];
        }

g<<k*2+1;
g.close();
}