Re-run your benchmark after making a few changes:

• Remove the say from your isSubsetHash sub wrapper. Scrolling a whole bunch of 1's up the terminal during the benchmark is guaranteed to throw your results way off.
• Rewrite your isSubsetHash to look like this:

  sub isSubsetHash {
      my $count = my @small = split ':', $_[0];
      my %big;
      @big{ split( ':', $_[1] ) } = ();
      exists( $big{$_} ) && $count-- for @small;
      !$count;
  }
  [download]

• Increase the size of your data set from two needles in a haystack of five, to six needles in a haystack of fifteen.

Removing say from the hash technique removes senseless IO operations that the other two techniques aren't testing.

The rewrite of the hash technique internalizes the loop used to build the hash, and takes advantage of the fact that an exists check is cheaper than a value check.

The increase of the data set size shows what the trend is as you try to upscale the different solutions. It's unlikely that the OP has a data set so small as only five elements in the haystack, and two in the needles set. In fact, it's unlikely that it's as small as 15 and 6. But it doesn't take much upscaling for the results of your benchmark to flip dramatically.

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.