Cod sursa(job #1489568)

Utilizator claug19ghit claudiu claug19 Data 21 septembrie 2015 17:35:12
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.31 kb
Raporteaza aceasta sursa 
using namespace std;
#include<fstream>
ifstream fin("fractii.in");
ofstream fout("fractii.out");
long long s;
int n,p[1000100];

int main()
{	fin>>n;
	int i,j;
	for(i=1;i<=n;i++)
		p[i]=i-1;
	for(i=2;i<=n;i++)
		{for(j=i*2;j<=n;j=j+i)
			p[j]=p[j]-p[i];
		s=s+p[i];
		}
	fout<<(s*2)+1;
return 0;
}