LeetCode 3423: Maximum Difference Between Adjacent Elements in a Circular Array

Meta Data

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Difficulty: easy First Attempt: 2025-07-17

• Submissions: Accepted (first try)

Approach

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Take the maximum absolute difference over adjacent pairs (Array Template 1). Circular means the last and first elements are adjacent too. In Python nums[-1] is the last element, so starting i at 0 and comparing with nums[i - 1] covers every adjacent pair at once.

My Solution

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class Solution:
    def maxAdjacentDistance(self, nums: List[int]) -> int:
        return max(abs(nums[i] - nums[i - 1]) for i in range(len(nums)))

I originally added abs(nums[-1] - nums[0]) separately, which is equivalent.

Complexity

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Time O(n), space O(1).

Mistakes to Avoid

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• Remember the ends are adjacent too.

Interview Explanation

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I take the maximum difference over adjacent pairs including last and first; comparing with nums[i - 1] from i = 0 naturally includes that pair. Time O(n).