I am working on a way to make random tests without a reference solution but Im not sure if I will manage to make them perfectly reliable, so for now I used your solution as a reference solution as it was the fastest of all of the submitted solutions so far.
Thank you very much for the advice, please let me know if there is anything else I should change :)

As I havn't made a kata before, I'm not sure what would be acceptable or not. Should I try to make a better performing solution myself or would it be acceptable to take a solution submitted by somebody else as a reference solution?

I misspelt the method name, idk how I didnt realise. Thanks

Thanks, I noticed that mistake in the example tests but forgot to fix it in the description.

Clarifying that ' alone does not count as a word would be nice.
Overall, it was a fun and interesting kata.