Cod sursa(job #662260)

Utilizator Stefex09Stefan Teodorescu Stefex09 Data 16 ianuarie 2012 11:58:53
Problema Fractii Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.33 kb
Raporteaza aceasta sursa 
#include<stdio.h>
int main()
{
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);
	long long  n,nr=0,i,j;scanf("%d",&n);
	long long *v;v=new long long [n];
	for(i=2;i<=n;i++) v[i]=i-1;
	for(i=2;i<=n;i++){
		for(j=i+i;j<=n;j+=i)
			v[j]-=v[i];
		nr+=v[i];
	}
	nr=2*nr+1;
	printf("%d",nr);
	return 0;
}