Cod sursa(job #2774613)

Utilizator BlaugranasEnal Gemaledin Blaugranas Data 12 septembrie 2021 06:59:25
Problema Fractii Scor 100
Compilator c-64 Status done
Runda Arhiva de probleme Marime 0.34 kb
Raporteaza aceasta sursa 
#include<stdio.h>
int n,i,k,x[1000001];
long long r=1;
int main()
{
	freopen("fractii.in","r",stdin),freopen("fractii.out","w",stdout),scanf("%d",&n);
	for(i=1;i<=n;++i)
       	x[i]=i;
	for(i=1;i<=n;++i)
        for(k=2*i;k<=n;k+=i)
            x[k]-=x[i];
	for(i=2;i<=n;++i)
       	r=r+2*x[i];
	printf("%lld",r);
	return 0;
}