The performance requirements are really high, I would rank it closer to a 2 kyu then a 3 kyu.
Good luck for other trying to solve it, if it timeout at the very end it is normal, try to keep optimizing your algorithm little by little until it passes.

Don't it deserve to be a 4 Kyu ?
Nice Kata however, it brought me back in my old maths :)

There are two mistakes in your code; the first one is that you can't sort something empty, hence you should add a check whether the string is null at the beginning; the second is that your list (sorted) is outside your function, therefore it doesn't reset itself and lead to several errors, you must re-init it at the beginning of your function.

Have a nice day :)

Hello, nice problem however i'm not sure that [performance challenge] should be specified in the title, it's working with a non-optimised python solution.

Have a nice day :)