Cod sursa(job #583383)

Utilizator ELHoriaHoria Cretescu ELHoria Data 19 aprilie 2011 20:44:08
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");

long long  s=0,a[1000000],j,n,i;

int main()
{   f>>n;

	for(i=2;i<=n;i++)
		if(!a[i])
		{
			s+=i-1;
			for(j=i*2;j<=n;j+=i)
				if(a[j])	a[j]-=a[j]/i;
				else a[j]=j-j/i;
		}
		else s+=a[i];

	g<<2*s+1;
	return 0;
}