Practice/Microsoft/Leetcode 189. Rotate Array

Leetcode 189. Rotate Array

CodingOptional

Problem

Given an integer array and a non-negative integer k, shift all elements in the array to the right by k positions. Elements that move beyond the end of the array should wrap around to the beginning.

For example, if you have [1, 2, 3, 4, 5] and shift right by 2, element at index 3 (value 4) moves to index 5, which wraps to index 0, giving [4, 5, 1, 2, 3].

Important: Modify the array in-place and return nothing. The function should directly alter the input array.

Requirements

1. Modify the input array in-place (do not allocate a new array for the final result)
2. Handle cases where k is greater than the array length
3. The solution should work for any valid integer values in the array
4. Function should return None (Python) or void (JavaScript/TypeScript)

Constraints

• 1 <= nums.length <= 10^5
• -2^31 <= nums[i] <= 2^31 - 1
• 0 <= k <= 10^5
• Time Complexity Target: O(n) where n is the array length
• Space Complexity Target: O(1) extra space (modifying in-place)

Examples

Example 1:

` Input: nums = [1, 2, 3, 4, 5], k = 2 Output: [4, 5, 1, 2, 3] Explanation:

• Rotate right by 1: [5, 1, 2, 3, 4]
• Rotate right by 2: [4, 5, 1, 2, 3] `

Example 2:

` Input: nums = [-1, -100, 3, 99], k = 2 Output: [3, 99, -1, -100] Explanation:

• Rotate right by 1: [99, -1, -100, 3]
• Rotate right by 2: [3, 99, -1, -100] `

Example 3:

Input: nums = [1, 2, 3], k = 4 Output: [3, 1, 2] Explanation: Since k=4 and length=3, effective rotation is k % 3 = 1