Seems very very very broken. The regex "[a]" apparently matches "crenel"
It's a bit confusing. Ticks on the left means it did match, ticks on the right means it didn't
Regex Golf
141–150 of 189 posts
Re: Regex Golf
#142For Abba... Why doesn't (.)(.)\2[^\1] work? I thought backreferences matched the captured literal, so negating it would match? But this looks the same as (.)(.)\2\1...
You cannot negate a capture, only a character literal. A capture might only be a character but it is NOT a literal,
Gotcha. That makes perfect sense. Thank you! :)
Re: Regex Golf
#143Re: Regex Golf
#144Re: Regex Golf
#145Me and a coworker totaled 3079 points. Anyone beat it?
Got hooked and to 3202, but ca 10-20 more points could be gained according to answers here and there: https://gist.github.com/jonathanmorley/8058871
Kudos to the author of the game, good job.
Re: Regex Golf
#146^(?!(..+)(\1)+$) Why does that work on primes? I got it by mistake when fiddling with the parenthesis locations but I was expecting to have to deal with xx separately.
Nice find. It works because it rejects "2 or more x's" repeated "2 or more times". So xx doesn't get rejected, but any multiple of that (xxxx, xxxxxx, ...) will be. The same way xxx doesn't get rejected, but any multiple of that (xxxxxx, xxxxxxxxx, ...) will be. You've solved it using the actual definition of prime numbers, no trickery needed. Well played. FYI, you don't need brackets around the \1, so can score 286.
More interesting than the definition of primes, it's almost the definition of multiplication that is embedded in this regex. We have two numbers(of occurrences) being multiplied:
- the first one is represented by the group (..+) it represents the number of occurrences n between 2 and +∞
- the second one is represented by (\1)+. We will repeat the first number m times, between 1 and +∞ times.
So the result of the multiplication is n*(m+1), which cannot be a prime. We just have to take the opposite with negative lookahead. It's very beautiful indeed.
See http://regex101.com/r/qN2fQ8 or http://www.regexper.com/#^%28%3F!%28..%2B%29\1%2B%24%29 to follow the above explanations.
Re: Regex Golf
#147(.+|)foo(.+|) Lol so awesome this. I oblige. Much love!
Powers: ^((((((((((x)\10?)\9?)\8?)\7?)\6?)\5?)\4?)\3?)\2?)\1?$ I feel like there's gotta be a sneakier way of doing this.
I did similarly, but managed to squeeze out a few more points:
^(((((((((xx?)\9?)\8?)\7?)\6?)\5?)\4?)\3?)\2?)\1?$
(60 points)
Re: Regex Golf
#148Earlier quoted context omitted.
569pts: ([^31]0|31|[017]2|[03]03|[^1]4|(900|01|7)5|6|[48]7|[57]8|09)$
Originally had 568, then saw this and improved. :) 580pts: 00(0$|3|6|9|12|15)|[^0]14|.53|^3[^38]|55|43|23|9.7
Nice. A smidge better at 582:
5[54]|2[437]|00($|[369]|1[25])|^8[17]|^3[29]|9.7Re: Regex Golf
#149Why is Kesha an optimal answer? (#2 k$) ;)
Re: Regex Golf
#150Earlier quoted context omitted.
^(?!.*(.)(.)\2\1) You may also need to fill in the places where it could be anything. The above worked on abba for me. BTW a double space indent then formats as code on HN I think.
Your approach scores higher, but it only matches the (imaginary) space before the "good" words. I went with: ^(?!. (.)(.)\2\1). $ with the thought that if I really wanted those matches I would want the whole strings. Fun game!
oops,
^(?!.*(.)(.)\2\1).*$