I'll start by pointing out that the two sorts you show are not identical. 

use List::Util qw( shuffle );

my @n = shuffle 5 .. 15;
print join( q{, }, sort @n ), "\n";
print join( q{, }, sort { $a <=> $b } @n ), "\n";
__END__
10, 11, 12, 13, 14, 15, 5, 6, 7, 8, 9
5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

[download]

That's because sort, by default, uses "cmp" rather than "<=>" for comparisons. That's sort of beside your point, however. A sort with the comparison unspecified will be faster than one that's explicit, and there's a convenient special case for "reverse sort". That's all good.

It's sort of beside the point of my meditation, however. The point here was to compare efficiency and speed. With the tied scalars, I was able to show that the heap method was more efficient—it did fewer comparisons. In spite of that, it was still slower because sort does its comparisons so much faster due to being optimized C.

In any case, thanks for your comment.

In reply to Re^2: A heap of medians: efficiency vs. speed by kyle
in thread A heap of medians: efficiency vs. speed by kyle

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.