#2951

Find the Peaks

newbie · 240 · lc easy +18 · verified · 75% accepted · 216 likes · top 86%

Description

Given a 0-indexed array mountain, identify every peak — an interior element that is strictly greater than both its immediate neighbors. The first and last positions can never be peaks.

Return the list of peak indices in any order.

Example 1:

Input: mountain = [2,4,4]

Output: []

Explanation: mountain[0] and mountain[2] can not be a peak because they are first and last elements of the array.

mountain[1] also can not be a peak because it is not strictly greater than mountain[2].

So the answer is [].

Example 2:

Input: mountain = [1,4,3,8,5]

Output: [1,3]

Explanation: mountain[0] and mountain[4] can not be a peak because they are first and last elements of the array.

mountain[2] also can not be a peak because it is not strictly greater than mountain[3] and mountain[1].

But mountain [1] and mountain[3] are strictly greater than their neighboring elements.

So the answer is [1,3].

Code

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class Solution:
    def findPeaks(self, mountain: List[int]) -> List[int]:

class Solution:
    def findPeaks(self, mountain: List[int]) -> List[int]: