Re: How can I reduce this with a REGEX?

maybe you'll consider hashes?

while(<DATA>){
%h = ();
undef $h{$1} while(s/(\d\d)//);
print join ("-", sort keys %h),"\n";
}

__DATA__
12-12
12-12-12
12-13-12-13
12-12-13-13
12-13-13-14
[download]

updated
$h{$1} = null became undef $h{$1}
thank you Mr. choroba

Comment on Re: How can I reduce this with a REGEX? Download Code

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Re^2: How can I reduce this with a REGEX? by choroba (Cardinal) on Mar 15, 2014 at 11:15 UTC
I would also use matching instead of substitution. You mentioned in a private message that the substitution is faster (using such a trick would be worth a comment), but my benchmark doesn't show the effect. To speed things up, rather use `my %h` instead of `%h = ()`. Read more... (959 Bytes) Output: `Rate lenno choro lenno 25358/s -- -4% choro 26458/s 4% --` [download] Perl 5.16.2, x86_64-linux-thread-multi. Update: Significantly faster: use a hash slice `undef @h{m/\d\d/g};` instead of the inner loop. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re^3: How can I reduce this with a REGEX? by Lennotoecom (Pilgrim) on Mar 15, 2014 at 18:56 UTC
Yes, thank you for your reply, I apparently got mistaken, I'm deeply sorry. You were right. My results: `use Benchmark(cmpthese); cmpthese(1000000, { 'a' => sub { $_ = '12-12-12-12-12'; undef $h{$1} while (s/(\d\d)//); }, 'b' => sub { $_ = '12-12-12-12-12'; undef $h{$1} while (m/(\d\d)/g); }, 'c' => sub { $_ = '12-12-12-12-12'; undef @h{m/\d\d/g}; } });` [download] results: `Rate a b c a 195427/s -- -19% -35% b 241896/s 24% -- -20% c 300933/s 54% 24% --` [download]	[reply] [d/l] [select]