This kata is a subject to deduplication process here: https://github.com/codewars/content-issues/issues/151.
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The example solution and the reference solution modify their input. That means in the random tests, the input will always be sorted already. In this case, that's not disastrous, but it's a bad habit to get into, because one day it might bite you subtly, but hard and painful. Therefore, do not teach this to solvers either. Test for input modification, and fail them if they do.

For this reason, somewhat satisfied.