I get a SIGABRT with my code. Surely, my code is wrong but I do not allocate any memory so how is it possible?

Besides, I'm seeing

Expected: "*&ikh)ihg&j'kj%&hij'-&'*ih)h'"

which should not be possible ("Every String consists of only lowercase letters and spaces.")

Using the very big hammer, nice.

This won't handle empty lists. Tests have been updated to check for that.

no it's not, the reference solution was using a + instead of *. fixed.

Ruby version: For "" (empty string) the expected return is false although all gs are happy. Is that correct?

That's a common feeling, it's okay to feel that. Just remember: you aren't stupid, and you weren't. Sometimes a one's mind can play tricks and block a way to the solution, even the simplest soulutions. But now you've made it, you've learned something new. Cheers! :)

i feel so stupid right now

I did not remember which variable the number pi was stored in, I was too lazy to find out about it at the time of solving the problem

It's always good to have a π along ;-)

indeed

Thanks, that was fast.

The initial code problem has been fixed, [Bool] is now [Word]. My apologies for this oversight.

Yes, it is unclear why tube sizes are passed. This is not Haskell-specific though.

ETA: if you have a Haskell-specific issue, consider prodding the translation author under the translation Suggestion. I may or may not get notifications for a new Issue, but I will get notifications for replies to my Suggestion ( because I authored that ).

Haskell version

The code template says "balanced :: [Bool] -> Bool" but the required type is
"balanced :: [Word] -> Bool".

Also it is unclear why tube sizes are passed if they are all the same (or 0).

This also groups repeated digits in the integral part.

repeating_fractions(221, 1) => "(2)1.0"

The regexp should probably be /(\d)(\1+)(?!..)/.

Finally a solution in O(n).