Cod sursa(job #722310)

Utilizator lostsoulMunteanu Florin lostsoul Data 24 martie 2012 16:18:35
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.32 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;
long long n,i,j,k,v[1000001];

int main()
{
	ifstream f("fractii.in");
	ofstream g("fractii.out");
	f>>n;
	k=0;
	for(i=1;i<=n;i++)
		v[i]=i;
	for(i=2;i<=n;i++)
		if(v[i]==i)
		for(j=i;j<=n;j+=i)
		{
			v[j]=v[j]/i;
			v[j]=v[j]*(i-1);
		}
	for(i=1;i<=n;i++)
		k+=v[i];


	g<<(k*2)-1;
	
}