Cod sursa(job #583013)

Utilizator informatician29kill03 informatician29 Data 17 aprilie 2011 12:40:43
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.34 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
const long long MAX_N=10000000;
	long long n,i,j,nr,euler[MAX_N]; 
int main() 
{
f>>n;nr=0;
for(i=2;i<=n;i++)
	euler[i]=i-1;
for(i=2;i<=n;i++) 
	for(j=2*i;j<=n;j+=i) 
		euler[j]-=euler[i];
for(i=2;i<=n;i++) 
	nr+=euler[i]; 
g<<2*nr+1;
}