[LeetCode][JavaScript]Wiggle Sort II

Wiggle Sort II

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?

https://leetcode.com/problems/wiggle-sort-ii/

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先是O(logn)的解法。

排序，双指针，p从头开始，q从中间开始，按照次序更新值。

/**
 * @param {number[]} nums
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var wiggleSort = function(nums) {
    var sorted = nums.slice(0).sort(sorting);
    var i = 0, p = 0, q = parseInt((sorted.length - 1) / 2 + 1);
    for(; i < sorted.length; i++){
        if(i % 2 === 0) nums[i] = sorted[p++];
        else nums[i] = sorted[q++];
    }
    return;

    function sorting(a, b){
        return a - b;
    }
};