Deduplicate - regex div by 4

[hobovsky]

From wiki list

1. Mod4 Regex

• 5 kyu
• Requires a partial match. Handling of square brackets can be additionally tricky. A bit quirky setup involving a class in Python.
• Satisfaction: 90% with 1,917 solutions
• 3 pending issues
• 4 languages, No pending translations
• Published: Nov 25, 2014
• Author last seen: Jun 2024

2. Regex for a decimal number divisible by 4

• 6 kyu
• Requires full match. Length limit of 50 characters, which allows for almost trivial solutions and does not make things any harder.
• Satisfaction: 90% with 412 solutions
• 3 pending issues
• 2 languages, No pending translations
• Published: Nov 22, 2018
• Author last seen: Mar 2025 (active)

[hobovsky]

I am not a fan of regex challenges, so I did not enjoy any of these:

• Kata 1. mixes many requirements together, like partial matches, square brackets markup, sign characters, leading zeros, etc. While these might make the task more challenging/interesting, they are a pain to test. It is also somewhat overranked.
• Kata 2. has a cleaner setup, possibly a better rank(?), but is newer, has a useless length limit, fewer languages, and fewer solutions.

I do not have any strong preference, but I think that out of the two I would keep 1. as older and with more variety than 2. And probably tests would have to be improved to include tricky cases.

[kolichj]

Length limit in kata 2 has a purpose:
Avoid silly solution with 25 variants of two last digits:
00|04|08|12|16|20|24|28|32.... etc