OK if there is no possibility of randomness. Approved and thanks!:)

I used the same tests as the C++ version. I can do them in a different -- but static -- order, since psuedorandomly generated tests aren't possible right now because of the way the rust runner is implemented on codewars (see https://github.com/Codewars/codewars-runner-cli/issues/240).

Good but could you randomize a bit your three parts of tests?

You are right, there is a typo in the answer but for the time being I'm not able to re-publish.
I only get:

Publishing Timed Out!
The server timed out while trying to publish your changes.
CANCEL

I'll tell you as soon I'm able to re-publish.
Thanks for your post!!!

Edit: able to fix it now.