Sorry for the slow response. Please see my answer to bonhart67 👍

Nice! I'm no guru on regex and hadn't been able to identify what was going wrong. You've helped me learn something, so cheers for that : )

Seems as though something's not quite right here. For example, the code results in "07.1.1.1" being valid, but "08.1.1.1" is not.

"127.0.0.1" is not valid either, although that could be blamed on the poor quality of the description and test cases given for the exercise.

The set of test cases for this kata need tightening up. I've found a number of published solutions that should not have been allowed to pass.

one C# solution, which has been marked up as being 'clever', even fails to pass the simple test [25, 50] => "YES".

Another published solution I found doesn't take into account the instruction to "sell the tickets strictly in the order people follow in the line" and fails the test [25, 25, 25, 100, 50, 50, 100, 25] => "NO".

Kata validation tests should properly reflect all given requirements.

This code fails for even the simplest test: [25, 50] => YES

The set of test cases needs fixing on this kata!