TikTok OA 面试真题解析：Rotate Array 数组右旋

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

Example 1:

Input: nums = [1,2,3,4,5,6,7], k = 3
Output: [5,6,7,1,2,3,4]

Explanation:

• rotate 1 step 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]

这道题要求将数组向右平移 k 步，核心是把末尾的 k 个元素搬到数组前面，同时保持其相对顺序不变。面试中常见的做法是先对 k 取模，避免当 k 大于数组长度时重复旋转；然后可以用额外数组直接拼接，也可以用“三次翻转”在原地完成，兼顾时间和空间效率。对于示例 [1,2,3,4,5,6,7] 和 k=3，最终结果是 [5,6,7,1,2,3,4]。