Cod sursa(job #283690)
| Utilizator |  Iagar Robert xblade |
Data | 19 martie 2009 15:57:25 |
|---|---|---|---|
| Problema | Fractii | Scor | 0 |
| Compilator | cpp | Status | done |
| Runda | Arhiva de probleme | Marime | 0.29 kb |
#include<fstream.h>
#define N 1000001
ifstream in("fractii.in");
ofstream out("fractii.out");
long long n,a[N];
int main()
{
in>>n;
long i,j,c=0;
for(i=1;i<=n;i++)
a[i]=i;
for(i=1;i<=n;i++)
{
for(j=2*i;j<=n;j+=i)
a[j]=a[j]-a[i];
c+=a[i];
}
out<<c;
return 0;
}