Cod sursa(job #332100)

Utilizator sseneca16vaida cosmin sseneca16 Data 16 iulie 2009 16:49:26
Problema Fractii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
#include<stdio.h>
//#define a 100000
 long long nr[1000001];
int n;
long b;

int main(void)
{
freopen("fractii.in","r",stdin);
freopen ("fractii.out","w",stdout);
scanf("%d",&n);
for(int i=1;i<=n;i++)
  nr[i]=i-1;
for(i=2;i<=n;i++)
   { for(int j=2*i;j<=n;j+=i)
	       nr[j]-=nr[i];
b+=2*nr[i];
}
b++;
printf("%d",b);



return 0;
}