LeetCode

Problem Statement

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]

Solution

func rotate(nums []int, k int) {
	n := len(nums)

	k = k % n

	reverse(nums, 0, n-1)
	reverse(nums, 0, k-1)
	reverse(nums, k, n-1)
}

func reverse(nums []int, i int, j int) {
	for i < j {
		nums[i], nums[j] = nums[j], nums[i]
		i++
		j--
	}
}