Cod sursa(job #282748)

Utilizator Sorin_IonutBYSorynyos Sorin_Ionut Data 18 martie 2009 10:09:48
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.5 kb
#include <stdio.h>

#define IN "fractii.in"
#define OUT "fractii.out"
#define max 1000111

FILE *fin=fopen(IN,"r");
FILE *fout=fopen(OUT,"w");

using namespace std;

long n;
long v[max];
long long sol;

int main()
{
 int i,j;

 fscanf(fin,"%ld",&n);
 fclose(fin);

 for(i=1;i<=n;i++)
  v[i]=i-1;

 for(i=1;i<=n;i++)
 {
  for(j=2*i;j<=n;j=j+i)
   v[j]=v[j]-v[i];

  sol+=v[i];
 // fprintf(fout,"%ld ",v[i]);
 }

 fprintf(fout,"\n%lld\n",2*sol+1);
 fclose(fout);

 return 0;
}