leecode/backlog/189.rotate-array.js
2020-05-22 18:17:19 +08:00

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/*
* @lc app=leetcode id=189 lang=javascript
*
* [189] Rotate Array
*
* https://leetcode.com/problems/rotate-array/description/
*
* algorithms
* Easy (29.07%)
* Total Accepted: 287.3K
* Total Submissions: 966.9K
* Testcase Example: '[1,2,3,4,5,6,7]\n3'
*
* 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?
*
*/
/**
* @param {number[]} nums
* @param {number} k
* @return {void} Do not return anything, modify nums in-place instead.
*/
var rotate = function(nums, k) {
// 就像扩容一样操作
k = k % nums.length;
const n = nums.length;
for (let i = nums.length - 1; i >= 0; i--) {
nums[i + k] = nums[i];
}
for (let i = 0; i < k; i++) {
nums[i] = nums[n + i];
}
nums.length = n;
};