324、Wiggle Sort II 摆动排序

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

Example:
(1) Given nums = [1, 5, 1, 1, 6, 4], one possible answer is [1, 4, 1, 5, 1, 6].
(2) Given nums = [1, 3, 2, 2, 3, 1], one possible answer is [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?

Credits:
Special thanks to @dietpepsi for adding this problem and creating all test cases
思路一：
这道题给了我们一个无序数组，让我们排序成摆动数组，满足nums[0] < nums[1] > nums[2] < nums[3]...，并给了我们例子。我们可以先给数组排序，然后在做调整。调整的方法是找到数组的中间的数，相当于把有序数组从中间分成两部分，然后从前半段的末尾取一个，在从后半的末尾去一个，这样保证了第一个数小于第二个数，然后从前半段取倒数第二个，从后半段取倒数第二个，这保证了第二个数大于第三个数，且第三个数小于第四个数，以此类推直至都取完

var wiggleSort = function(nums) {
    nums.sort(function(a,b){
        return a-b;
    })
   
    var tmp=nums.concat();
    var c=Math.ceil(nums.length/2-1);
    var b=nums.length-1
    console.log(c,b)
    for(var i=0;i