189. Rotate Array

1. Description

Given an array, rotate the array to the right by k steps, where k is non-negative.

2. Example

Example 1:
Input: nums = [1,2,3,4,5,6,7], k = 3
Output: [5,6,7,1,2,3,4]
Explanation:
rotate 1 steps to the right: [7,1,2,3,4,5,6]
rotate 2 steps to the right: [6,7,1,2,3,4,5]
rotate 3 steps to the right: [5,6,7,1,2,3,4]

Example 2:
Input: nums = [-1,-100,3,99], k = 2
Output: [3,99,-1,-100]
Explanation:
rotate 1 steps to the right: [99,-1,-100,3]
rotate 2 steps to the right: [3,99,-1,-100]

3. Constraints

• 1 <= nums.length <= $2 * 10^4$
• $-2^{31}$ <= nums[i] <= $2^{31} - 1$
• 0 <= k <= $10^5$

4. Follow Up

• Try to come up with as many solutions as you can. There are at least three different ways to solve this problem.
• Could you do it in-place with O(1) extra space?

5. Solutions

My Accepted Solution(Follow Up)

n = m_nums.size()
Time complexity: O(n)
Space complexity: O(1)

class Solution {
public:
    void rotate(vector<int> &m_nums, int k) {
        k %= m_nums.size();

        reverse(m_nums.begin(), m_nums.end());

        reverse(m_nums.begin(), m_nums.begin() + k);
        reverse(m_nums.begin() + k, m_nums.end());
    }
};