Cod sursa(job #731409)

Utilizator ScateWayScateWay ScateWay Data 7 aprilie 2012 23:45:30
Problema Fractii Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.3 kb
Raporteaza aceasta sursa 
#include<stdio.h>
long n,i,j,a[1000001];
long long s;
int main()
{freopen("fractii.in","r",stdin);
freopen("fractii.out","w",stdout);
scanf("%ld",&n);
for(i=1;i<=n;i++) a[i]=i-1;
for(i=2;i<=n;i++) for(j=2;i*j<=n;j++) a[i*j]-=a[i];
s=1;
for(i=1;i<=n;i++) s+=2*a[i];
printf("%l;d",s);
return 0;
}