Beefy Boxes and Bandwidth Generously Provided by pair Networks
more useful options

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
Well both of my solutions have been beaten so I am willing to post them. But there are still a couple of hours for people to try to beat the current entries. But right now I am in a quandry about who is leading in the first. The best solution so far is 47 characters. It is basically MeowChow's solution with a trivial fix from chipmunk. I feel that it is "really" MeowChow's, but technically it was chipmunk who posted it. I will have to decide what to do with that one. For the bonus round tye is clearly leading.

What I did differently than everyone else is I used a hash. My idea was to use a hash and then mark off entries by assigning to a hash reference. If you assign a range of numbers starting with an odd, the odds conveniently become the keys. This unfortunately makes 2 a special case. For the general problem I snuck 2 past like this in 60 characters:

sub p{ %p=@_=3..1+pop;@p{2,map$f*$_,@_}=$f=$_ for@_;grep$p{$_},2,@_ }
For the second problem I just dropped the special logic for 2 and stuck it at the beginning of the list with this 61 character solution:
sub p{ 2,grep{$f=$_,@p{map$f*$_,3..$_[0]/$f}=0if$p{$_}}%p=3..1+$_[0] }
The observant will notice that this is indeed startlingly similar to tye's solution. If he tried to reverse-engineer mine, the copy is better than the original! (Possibly because he did not have my blind spot for using a hash...)

In reply to Re (tilly) 1: (Golf): Sieve of Eratosthenes by tilly
in thread (Golf): Sieve of Eratosthenes by tilly

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others lurking in the Monastery: (3)
    As of 2018-06-24 07:19 GMT
    Find Nodes?
      Voting Booth?
      Should cpanminus be part of the standard Perl release?

      Results (126 votes). Check out past polls.