Cod sursa(job #314126)

Utilizator EugenStoicaEugen Stoica EugenStoica Data 10 mai 2009 17:21:53
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.33 kb
Raporteaza aceasta sursa 
#include<stdio.h>

int main()
{
unsigned long long int n,v[1000001]={0},i,j,sol=0;
freopen("fractii.in","r",stdin);
freopen("fractii.out","w",stdout);
scanf("%lld",&n);
for(i=1;i<=n;i++)v[i]=i-1;
for(i=2;i<=n;i++)
	{
	for(j=2*i;j<=n;j=j+i)
		v[j]=v[j]-v[i];
	sol=sol+2*v[i];
	}
sol++;
printf("%lld",sol);
return 0;
}