🎯"Maximum Difference Between Adjacent Elements in a Circular Array" LeetCode 3423 (C++ | JavaScript | Python)

Hey problem solvers! 🎯

Today we’re tackling a fun and elegant problem from LeetCode — 3423: Maximum Difference Between Adjacent Elements in a Circular Array. This one checks your understanding of array boundaries and circular behavior. Let’s break it down. 🔍

📜 Problem Overview

You're given a circular array nums, and your task is to find the maximum absolute difference between adjacent elements, where:

• The first and last elements are also considered adjacent (because it's circular).
• You return the maximum absolute difference between any two adjacent numbers.

✨ Example

Input: nums = [1, 2, 4]
Output: 3
Explanation:
Adjacent pairs: |1 - 2| = 1, |2 - 4| = 2, |4 - 1| = 3.
Max is 3.

🧠 Intuition

The array is circular, so both regular adjacent pairs and the pair between the last and first element must be considered.

Strategy:

• Initialize ans with |nums[0] - nums[n-1]|.
• Iterate through the array and compute |nums[i] - nums[i+1]| for all valid i.
• Return the maximum of all these values.

⚙️ C++ Code

class Solution {
 public:
  int maxAdjacentDistance(vector<int>& nums) {
    int ans = abs(nums.front() - nums.back());

    for (int i = 0; i + 1 < nums.size(); ++i)
      ans = max(ans, abs(nums[i] - nums[i + 1]));

    return ans;
  }
};

🌐 JavaScript Version

var maxAdjacentDistance = function(nums) {
    let ans = Math.abs(nums[0] - nums[nums.length - 1]);

    for (let i = 0; i + 1 < nums.length; ++i) {
        ans = Math.max(ans, Math.abs(nums[i] - nums[i + 1]));
    }

    return ans;
};

🐍 Python Version

def maxAdjacentDistance(nums):
    ans = abs(nums[0] - nums[-1])

    for i in range(len(nums) - 1):
        ans = max(ans, abs(nums[i] - nums[i + 1]))

    return ans

🧪 Test Cases

Input: nums = [1, 2, 4]
Output: 3

Input: nums = [-5, -10, -5]
Output: 5

Input: nums = [0, 100, -100]
Output: 200

⏱ Time & Space Complexity

Time Complexity: O(n) — one pass through the array
Space Complexity: O(1) — constant extra space

✅ Wrap-Up

This is a great warm-up problem to train your attention to edge conditions like circular connections. Simple logic and clean implementation go a long way here.

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Happy coding! 🚀