I know this is an old comment, so this is for whoever sees this.
Ruby seems like a bit of an outlier, as it's naturally less verbose
than most other languages. At least in my experience, once you become
familiar with all of the most commonly used ruby methods, one liners
like this can actually be just as understandable (if not more so) as
more verbose code.

I failed to realize too facepalm. My degree is crying right now LMAO

I get it haha but I swear it didn't stop my brain from making dialup noises after seeing it lmao

That ternary boolean return is just... O.o

Fair enough, but it kinda defeats the point lol

Truthy vals are really useful. e[regexp] would be considered "truthy" if
a match is found, and "falsey" otherwise.

LMAO. 10/10 for ignoring the authors rules completely XD

short, but where's the Regex? this is "Regexp Basics" after all ;)

Clever, BUT... this isn't Regex :/

I did this too at first, but I figured a realistic solution would
return a new array, rather than modify existing ones.

This is actually a correct solution, it just relies very heavily on math, rather than on programming.

I'm curious how you went about determining this formula? Perhaps I'm just rusty,
but I really couldn't come up with anything that worked past n = 6 because of
the "XXXXXV" = "LIIIII" problem.

Mine isn't quite 3 lines, but recursion is certainly helpful on this one ^-^

But...why? lol