Cod sursa(job #275259)
Utilizator | Data | 10 martie 2009 12:37:17 | |
---|---|---|---|
Problema | Fractii | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.36 kb |
#include<fstream.h>
#include<math.h>
ifstream fin("fractii.in");
ofstream fout("fractii.out");
long a[100001],n,s,i,j;
int main()
{
fin>>n;
for(i=1;i<=n;i++)
a[i]=i-1;
s=0;
for(i=1;i<=n;i++)
{
for(j=2*i;j<=n;j=j+i)
a[j]=a[j]-a[i];
s=s+a[i];
}
fout<<2*s+1;
return 0;
}