7. Rotate Array

Medium · Array

Given an array and a rotation count, rotate the array to the right by k steps. Rotation means moving elements from the end of the array to the beginning.

For example, rotating [1, 2, 3, 4, 5] right by 2 steps gives [4, 5, 1, 2, 3].

You must solve this in-place with O(1) extra space (not counting the output array itself).

Examples

Example 1
Input: nums = [1, 2, 3, 4, 5], k = 2
Output: [4, 5, 1, 2, 3]
Explanation: Rotate right by 2: take the last 2 elements [4, 5] and move them to the front.
Example 2
Input: nums = [1, 2, 3, 4, 5], k = 7
Output: [4, 5, 1, 2, 3]
Explanation: k = 7 is equivalent to k = 2 (since 7 % 5 = 2). Rotate right by 2 steps.

Constraints