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189 Javascript Solution to Rotate Array Problem from Leetcode

Rotate Array

Easy
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?

Javascript Solution

const rotateArray = (nums, k) => {
  nums.unshift(...nums.splice(nums.length - k));
  return nums
}

Example Input

console.log(rotateArray([1,2,3,4,5,6,7,8,9], 3));

Output

[ 7, 8, 9, 1, 2, 3, 4, 5, 6 ]

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