Reverse an Array

Implement reverseArray

Given an array of integers nums, reverse the array in-placeIn-PlaceModifying the original data directly, without allocating a separate array or data structure to hold the result. Uses only O(1) extra space. and return it. Do not use a second array for the optimal solution — swap elements directly within nums using two pointers moving toward each other from opposite ends.

Example 1:

Input: nums = [6,1,9,3]

Output: [3,9,1,6]

Example 2:

Input: nums = [8]

Output: [8]

Example 3:

Input: nums = [4,4,2,4]

Output: [4,2,4,4]

+ 4 hidden test cases run on Submit.

Constraints:

  • 1 ≤ nums.length ≤ 10⁵
  • -10⁹ ≤ nums[i] ≤ 10⁹
  • Reverse the array in-place — do not allocate a second array for the optimal solution

nums =

[6, 1, 9, 3]