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🔥Reverse Array In-Place: O(1) Memory InversionEasy
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Reverse Array In-Place: O(1) Memory Inversion

Targeted in FAANG & Tech OA:GoogleAmazonMicrosoftSwiggy
Real-World Engineering Context
Undo stack history inversion, GPU vertex winding order reversal, and audio sample time-reversal DSP processing.
Given an array `arr`, reverse the elements in-place and return the mutated array without allocating another array of length n.

Sample Test Cases

Input: [[1,2,3,4,5]]
Expected: [5,4,3,2,1]
Input: [[10,20]]
Expected: [20,10]
Input: [[42]]
Expected: [42]

Constraints

  • 0 <= arr.length <= 10^5
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