Re: Re: (Golf): Sieve of Eratosthenes

[chipmunk]

in reply to Re: (Golf): Sieve of Eratosthenes
in thread (Golf): Sieve of Eratosthenes

I think that undef is not prime. :)

But at 47 characters I think MeowChow still won't be beat:

sub sieve {
  sub p{$_[0],@_>1?p(grep$_%$_[0],@_):()}p 2..pop
}

[MeowChow]

I had thought of that, but assumed it would slide :)

Make that 46 by the way...

sub sieve {
  sub p{$_[0],$#_?p(grep$_%$_[0],@_):()}p 2..pop
}

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

[chipmunk]

I had thought of that, but that goes into deep recursion if you call sieve(1). :)

Oh, but tilly says that you may assume $n is above a fixed number. Pooh!

[tilly]

No. I only say that for the bonus problem.

The first problem is correct first, efficient afterwards. The second should express the efficient algorithm accurately, but I allow some boundary sloppiness.

[MeowChow]

Abusing the rules for fun and profit (46 chars):

sub sieve {
  sub p{$_[0],@_>1?p(grep$_%$_[0],@_):1}p 2..pop
}

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print