why would that be inefficient? starting with python now and I used sorted() as well.
what do you mean by "O(n log n)"?

you can view their solution by clicking on 'View Solution'

can you solve it by o(n) please?

No you cant do that, it would contain 0 and we dont want that

Just a heads up:

Kata directions: "Do not mutate the input array/list." This solution mutates the input array.

The code will not work correctly for double digit scores. But this particular kata only tests for scores from 0 to 4 on each side.

Lots of good variations for this simple question. But for my money, this is the easiest to read.

I think @AndrewB31415 was suggesting that there is a different approach that doesn't require iterating through a string of the input (*see his solution). But if you use this approach then you do need to convert the input number to an iterable.