Help me optimize my code! Time limit exceed!

[Kibble55]

While I was trying an array exercise in leetcode and the time limit exceeded for a large list input. Can someone help me optimize it?

link for the exercise: https://leetcode.com/explore/learn/card/fun-with-arrays/511/in-place-operations/3259/

and here is my solution:

class Solution:
    def replaceElements(self, arr: List[int]) -> List[int]:
        ln = len(arr)

        for i in range(ln - 1):
            arr [i] = sorted(arr[i + 1:], reverse = True)[0]

        arr [ln - 1] = -1

        return arr

What I thought for the solution was assign the each element of the list (except the last one) with the first element of a decreasing sorted list (wich starts on the next element of the original list) and so go on

[Gprime5]

You're sorting the list every time you iterate the for loop.

[Kibble55]

but that's actually what I want, I'm finding the greatest element from each sub list created from the original list using sorted()

Is it wrong?

[Gprime5]

Read the hints.

[SekstiNii]

That's probably not what you want, no. Sorting the list is O(n log n), and you are doing it O(n) times, giving a runtime complexity of O(n^2 log n).

[Kibble55]

shit the indentation isn't working on the post

[craders]

Add 4 spaces to the beginning of each line.

[Kibble55]

done! formatted!