3423 Maximum Difference Between Adjacent Elements in a Circular Array

Fairly straightforward, try not to directly jump into the $mod$ operator looking at the ‘circular’ array wording.

We can scan the array regularly and keep track of the max abs difference - but this time also check the last and the first element because in a circular setting that is the only combination which would be missed and all others will be duplicate.

Code

Python3

class Solution:
    def maxAdjacentDistance(self, nums: List[int]) -> int:
        if not nums:
            return 0
 
        nums.append(nums[0])
 
        res = -math.inf
        for a, b in itertools.pairwise(nums):
            res = max(abs(a - b), res)
 
        return res

Big O Analysis

• Runtime

  The runtime complexity here is $O(N)$ since we are visiting all elements in the array only once.

• Memory

  The memory usage is $O(1)$ since we do not use any extra data structure.

— A

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