It's possible, but any real Haskeller will never use length and !! only reluctantly - precisely because linked lists are not arrays.

Actually, xs !! (length xs - 2) would still be O(n). That too would go against the essence of the kata though.

Oh never mind. But I'm still not making a JS translation.

Though... I have written a Rust translation that has been approved. I didn't know the original language was Haskell. Though... I am not sure it makes such a difference, it's possible to write a similar solution based on indices in Haskell...

Ah, sorry, the original translation was already approved. I thought you resurrected it. Never mind!

I haven't written the translation, I only made decent tests (look diff ;)).

Was it a good idea to translate this kata to Python?

Linked lists are not arrays and arrays are not linked lists; the essence of the kata seems lost in translation.