I mean it's only a 6 kyu task and it has a regex tag, so it was kind of implied, that it should probably be solved with a simple regex.

$ sign wasn't even necessary.

Treating the whole array as a string is even better instead of iterating over it :)

Would have saved myself alot of time with this approach vs. writing a million if statements.

Yes, there's a difference. Your solution in fact more performant than the OP's solution. His solution has O(n^2) time complexity and yours is O(n) meaning it's much faster.

I tried to go this route, but I did not have in mind to merge the two like that.
Such a brilliant solution!

regex is amazing.

Same here, I couldn't figure out how to implement regex like this one then I gave up xD.

Nice!

I tried to go down this route, but couldn't figure out where to put the $ sign

RegExp don't work like that brother. It will just check only one single character inside the bracket as if you write like you've shown. Check https://regexlearn.com/cheatsheet .

damn this regex again.

this regExp is a must to learn bro

very cool :)

Oh my goodness, regex can do pretty much everything.

because regex will check for match of single character from inside brackets. Check https://regex101.com/ for explanation of this one.