Rotate Array

// 189. Rotate Array // // https://leetcode.com/problems/rotate-array/ // rotate function rotates the nums slice by iterating the number with k. // Time complexity O(n) & non-additional memory is the way with reserve the slice several times. // For about k, only k mod the length of the nums slice is required to rotate the slice. // Reverse index 0 to len(nums) - 1. // Reverse index 0 to k - 1. // Reverse index k to len(nums) - 1. func rotate(nums []int, k int) { k %= len(nums) reverse := func(nums []int, start, end int) { for start < end { nums[start], nums[end] = nums[end], nums[start] start++ end-- } } reverse(nums, 0, len(nums)-1) reverse(nums, 0, k-1) reverse(nums, k, len(nums)-1) }