Cod sursa(job #395260)

Utilizator mihai995mihai995 mihai995 Data 12 februarie 2010 17:32:39
Problema Fractii Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.28 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
int v[1000001];
int main()
{
	int i,j,n,nr=0;
	ifstream f("fractii.in");
	ofstream o("fractii.out");
	f>>n;
	for (i=2;i<=n;i++)
	{
		v[i]=v[i]+i-1;
		for (j=2*i;j<=n;j+=i)
			v[j]-=v[i];
		nr+=v[i];
	}
	o<<2*nr+1;
	return 0;
}