# LeetCode 189. Rotate Array

## Description

https://leetcode.com/problems/rotate-array/

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

Example 1:

```Input: `[1,2,3,4,5,6,7]` and 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: `[-1,-100,3,99]` and 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]
```

Note:

• Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
• Could you do it in-place with O(1) extra space?

## Explanation

Use a temp array to store the element in rotating order

## Python Solution

``````class Solution:
def rotate(self, nums: List[int], k: int) -> None:
"""
Do not return anything, modify nums in-place instead.
"""
temps = []

for i in range(len(nums) - k, len(nums)):
temps.append(nums[i])

for i in range(0, len(nums) - k):
temps.append(nums[i])

for i in range(0, len(nums)):
nums[i] = temps[i]     ``````
• Time complexity: O(N).
• Space complexity: O(N).