189. Rotate Array

Source code notebook Author Update time

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

Follow up:

  • 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?

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]

Constraints:

  • 1 <= nums.length <= 2 * 104
  • -231 <= nums[i] <= 231 - 1
  • 0 <= k <= 105
# @lc code=start
using LeetCode

function rotate_arr(nums::Vector{Int}, k::Int)
    k %= length(nums)
    reverse!(nums)
    reverse!(@view nums[1:k])
    reverse!(@view nums[k+1:end])
    nums
end
# @lc code=end
rotate_arr (generic function with 1 method)

This page was generated using DemoCards.jl and Literate.jl.