This is one of the shorter solutions that are using regex. I doubt that the beginning part of the regex " *" will match all whitespace characters. Consider using "\s*" instead. Probably works only because current test cases don't contain other whitespace like \t characters before the comment marker.

Also, this regex works only if the comment markers are single characters.

Yes. I guess the fact that there are at least 3 possible reasons is enough to have more "clever" than "best practice" :-)

It's impossible to answer this question, this is just what people voted, each one may have their reason.

Nice; I never saw Result before - thanks for the teaching!

I think this wording could be improved. I understood this rule to mean that the loop wouldn't have 1 follow 9, unless there was a 0. Therefore: 901 would be good, but 912 would not.

A second sentence like this one would help: "a sequence will not roll over after the last digit, so 1 will never follow 0"

k it was a brainfart

This can be checked pretty easily:

> "".join(str(n) for n in range(1, 10000)).index('4949')
18685

Hi,

I tested 8 solutions in python/JS (most upvoted and users I trust about having a proper solution) and they all find 18685 for that input. Now,I'm not entirely sure which one of yours or the translator's solution found 18683 when I read your sentence. Could you clarify, plz?

I was pressing attempt multiple times to make sure my code isnt making any very rare mistakes,
and I think I found a mistake in the c# translation author's solution.
It thinks that the index of 4949 should be 18685 when its actually two less (18683)
This is really rare and you can easily pass the random tests but i thought id mention it.

that's right :) Thanks

the ?: operator is useless here. the left of the ? already returns your bool

I spent like 1.5 hours on this and got the shortest solution this kata has so far I think :D
so please press clever on it

thanks for this. I learned more about regexes and will use this info if i can :D