Cod sursa(job #490698)

Utilizator 6301263George 6301263 Data 7 octombrie 2010 15:51:16
Problema Fractii Scor 40
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.34 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;
int main()
{
	ifstream f("fractii.in");
	ofstream g("fractii.out");
	
	unsigned long q,n,h[1000000],i,total=0;
	f>>n;
	for(i=2;i<=n;i++)
	{
		h[i]=i-1;
	}
	for(i=2;i<=n;i++)
	{
		total+=h[i];
		for(q=i+i;q<=n;q+=i)
			h[q]-=h[i];
	}
	g<<total*2+1;
	f.close();
	g.close();
	return 0;
}