It would be great if the random tests could be given an individual heading, or even consecutive numbering. Now every random test has the same name: Input text, Correct answer, and Answer returned.

For point 2, the problem description should be clear which associativity to use, even if both left and right are mathematically correct. If this is not the case, please raise an issue.

oof, I think that should have been mentioned

You can avoid a copy with a simple syntax making it quite similar to using a unique pointer in C (cf this kumite not to spoil others in comments)

how about adding the spoiler tag, djeezes

Oops lol

I don't know, this kata feels more than different enough from the other one to me.

I was able to solve the other one much faster than this one, at least.

Is this a duplicate?:
Greatest common divisor as linear combination

You both make hard kata's!

Thanks mate! I can always trust you to solve my katas :)

Honestly, I feel a bit bad that I'm often unnable to solve yours, lol.

The problem is I never solved a Rubik's cube in my life. I don't even understand basic patterns to move a piece from A to B without moving other pieces.

I can only do that after I have solved the kata.

why can't you edit them?

Rank inflation is a thing to consider too

This is a selffulling propecy. Skrew this inflation :)

Your 2x2 kata is probably also 4, no?