Cod sursa(job #374447)
Utilizator | Ivan Nicolae Darth_Niculus | Data | 17 decembrie 2009 03:22:08 |
---|---|---|---|
Problema | Fractii | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.56 kb |
/* Ivan Nicolae - Fractii */
#include <stdio.h>
#define NMAX 1000001
#define _fin "fractii.in"
#define _fout "fractii.out"
long n,i,A[NMAX];
int main()
{
freopen(_fin,"r",stdin);
freopen(_fout,"w",stdout);
scanf("%ld",&n);
for (i=1;i<=n;i++)
A[i]=i-1;
for (i=2;i<=n;i++)
{
long k=2;
while (k*i<=n)
{
A[k*i]-=A[i];
k++;
}
}
long sum=0;
for (i=1;i<=n;i++)
sum+=A[i];
sum*=2; sum++;
printf("%ld\n",sum);
fclose(stdin);
fclose(stdout);
return 0;
}