Reverse an Array

Problem Reverse an array arr[]. Reversing means the first element becomes last, the second becomes second-last, and so on. Example 1: Input: arr = [1, 4, 3, 2, 6, 5] Output: [5, 6, 2, 3, 4, 1] Example 2: Input: arr = [4, 5, 1, 2] Output: [2, 1, 5, 4] Approaches Using Two Pointers (O(n) time, O(1) space) Swap elements from start and end until you reach the middle. def reverse_array(arr): left, right = 0, len(arr) - 1 while left < right: arr[left], arr[right] = arr[right], arr[left] left += 1 right -= 1 arr = [1, 4, 3, 2, 6, 5] reverse_array(arr) print(arr) Output: [5, 6, 2, 3, 4, 1] Swapping Elements by Index (O(n) time, O(1) space) Iterate through the first half and swap with corresponding elements from the end. def reverse_array(arr): n = len(arr) for i in range(n // 2): arr[i], arr[n - i - 1] = arr[n - i - 1], arr[i] arr = [1, 4, 3, 2, 6, 5] reverse_array(arr) print(arr) Output: [5, 6, 2, 3, 4, 1] Using Inbuilt Method (O(n) time, O(1) space) def reverse_array(arr): arr.reverse() arr