Suppose we have a list of numbers called nums. We have to find the index of every peak element in the nums, sorted in ascending order. An index i of a peak element when all of these three conditions are satisfied: 1. The next number on its right that's different than nums[i] doesn't present or must be smaller than nums[i] 2. The previous number on its left that's different than nums[i] doesn't present or must be smaller than nums[i] 3. There is at least one number on its left side or right side that is different from nums[i].
So, if the input is like nums = [5, 8, 8, 8, 6, 11, 11], then the output will be [1, 2, 3, 5, 6], because the plateau of 8s are considered as peaks [1,2,3]. And 11s are also, [5, 6].
To solve this, we will follow these steps −
Let us see the following implementation to get better understanding −
def solve(nums): n = len(nums) ans =  i = 0 while i < n: i0 = i while i < n and nums[i] == nums[i0]: i += 1 if (i0 == 0 or nums[i0] > nums[i0 - 1]) and (i == n or nums[i0] > nums[i]): if i0 != 0 or i != n: ans.extend(range(i0, i)) return ans nums = [5, 8, 8, 8, 6, 11, 11] print(solve(nums))
[5, 8, 8, 8, 6, 11, 11]
[1, 2, 3, 5, 6]