Well, I pointed to the link with the discussion:
http://kw.pm.org/wiki/index.cgi?ListShuffle
...but here is a quick summary.

Your algorithm (and my mostly equivalent one) are memory expensive because they have to allocate for a random number for each element in the list. If you are sorting numbers, this amounts to a doubling of the memory footprint.

It is slow because it is two pass, the first O(N), the second (the sort) O(NlogN). That's not terribly slow, but list shuffling can be accomplished with O(N) running time. So, a pure perl swap-shuffle is about 4 times faster, and the List::Util version is about 70 times faster, depending, of course on list-size.

In reply to Re^4: Is this a fair shuffle? by fishbot_v2
in thread Is this a fair shuffle? by Roy Johnson

Title:
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, details, 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, summary, 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.