Return to Answer

fix

Source Link

edited Dec 31, 2011 at 0:37

Perl regex, 2424 69

^(.(.+)(?=\2{$a=$+})(.$|(??{"\Q$a"})(?{$a=substr$a,1}))*(?(?{''eq$a})$|(*F))

Obviously not a genuine CS regular expression, but those modern recursive regexes can work wonders~~but those modern recursive regexes can work wonders~~ and the edited (but fixed) version is not that short at all. I'm starting to wonder if actual Perl code, with the ability to reverse the starting string, wouldn't be shorter than that.

Perl regex, 24

^(.(.+)(?=\2)(.$|(?1)))

Obviously not a genuine CS regular expression, but those modern recursive regexes can work wonders.

Perl regex, 24 69

^.(.+)(?{$a=$+})((??{"\Q$a"})(?{$a=substr$a,1}))*(?(?{''eq$a})$|(*F))

Obviously not a genuine CS regular expression, ~~but those modern recursive regexes can work wonders~~ and the edited (but fixed) version is not that short at all. I'm starting to wonder if actual Perl code, with the ability to reverse the starting string, wouldn't be shorter than that.

Source Link

created Dec 30, 2011 at 10:44

J B

Perl regex, 24

^(.(.+)(?=\2)(.$|(?1)))

Obviously not a genuine CS regular expression, but those modern recursive regexes can work wonders.