324. Wiggle Sort II

324. Wiggle Sort II

 ---擺動排序問題

Given an unsorted array nums, reorder it such that nums[0] < nums[1] > nums[2] < nums[3]....

Example 1:

Input: 
Output: One possible answer is .nums = [1, 5, 1, 1, 6, 4][1, 4, 1, 5, 1, 6]

Example 2:

Input: 
Output: One possible answer is .nums = [1, 3, 2, 2, 3, 1][2, 3, 1, 3, 1, 2]

Note:
You may assume all input has valid answer.

Follow Up:
Can you do it in O(n) time and/or in-place with O(1) extra space?