Cod sursa(job #256984)

Utilizator siminescuPaval Cristi Onisim siminescu Data 12 februarie 2009 16:59:22
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.32 kb
Raporteaza aceasta sursa 
#include <fstream.h>   
ifstream f("fractii.in");   
ofstream g("fractii.out");   
int main()   
{   
long long a[1000001],i,n,j,p=0;
f>>n;
for(i=2;i<=n;i++)
	a[i]=i;
for(i=2;i<=n;i++)
    { if(a[i]==i)
    for(j=i;j<=n;j=j+i)
		a[j]=a[j]/i*(i-1); }
for(i=2;i<=n;i++)
p=p+a[i];
g<<2*p+1;   
return 0;   
}