Cod sursa(job #227973)

Utilizator ditiBilescu Adrian diti Data 5 decembrie 2008 23:30:08
Problema Fractii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.35 kb
Raporteaza aceasta sursa 
#include<stdio.h>
FILE*f=fopen("fractii.in","r"),*g=fopen("fractii.out","w");
long long unsigned a[1000002],n,i,j,s;
int main()
{
  fscanf(f,"%llu",&n);
 for(i=2;i<=n;++i)
  {if(a[i]==0) 
    {s+=i-1;
 for(j=i;j<=n;j+=i)
   if(a[j])a[j]-=a[j]/i;
   else a[j]=j-j/i;
     }
   else s+=a[i];    
   }
 fprintf(g,"%llu",s*2+1);
return 0;
}