
Given an integer array nums , reorder it such that nums[0] < nums[1] > nums[2] < nums[3]... .
You may assume the input array always has a valid answer.
1 <= nums.length <= 5 * 10 ^40 <= nums[i] <= 5000It is guaranteed that there will be an answer for the given input nums .Follow Up: Can you do it in O(n) time and/or in-place with O(1) extra space?