Maximize the Topmost Element After K Moves — LeetCode 2202 Python Solution

The problem

You are given a 0-indexed integer array nums representing the contents of a pile, where nums[0] is the topmost element of the pile. In one move, you can perform either of the following: If the pile is not empty, remove the topmost element of the pile.

Example

Input

nums = [5,2,2,4,0,6], k = 4

Output

5

Explanation

One of the ways we can end with 5 at the top of the pile after 4 moves is as follows:

Python solution

class Solution:
    def maximumTop(self, nums: List[int], k: int) -> int:
        if k == 0:
            return nums[0]
        n = len(nums)
        if n == 1:
            if k % 2:
                return -1
            return nums[0]
        ans = max(nums[: k - 1], default=-1)
        if k < n:
            ans = max(ans, nums[k])
        return ans

Complexity

Pattern: Greedy

Take the locally best option every time — when you can prove that never costs you later. LeetCode 2202. Maximize the Topmost Element After K Moves is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Greedy.

The greedy guide has the Python template for the pattern and the 346 LeetCode problems that use it.

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