Bubble Sort
Traversal in Binary Tree：

在遍歷一數列的時候，依據特定運算條件(ex.a > b, a < b)，
來比對或進行交換，並完成運算後的排序。

Input: nums = [1, 2, 3, 2, 1, 6]

let bubbleSort = (nums) => {
  for (let i = nums.length; i >= 0; i--) {
    for (let j = nums.length; j >= 0; j--) {
      if (nums[j] < nums[j - 1]) {
        let box = nums[j]
        nums[j] = nums[j - 1]
        nums[j - 1] = box
      }
    }
  }
  return nums
};

Output: newNums = [1, 2, 2, 3, 1, 6]

Flow Chart:

[ 1, 2, 3, 2, 5, 6 ]
[ 1, 2, 3, 2, 5, 6 ]
[ 1, 2, 3, 2, 5, 6 ]
[ 1, 2, 2, 3, 5, 6 ]
        .
        .
        .
[ 1, 2, 2, 3, 5, 6 ]       

Blog：http://52.198.119.162/關於bubble-sort排序方法與示意圖/
LeetCode：http://52.198.119.162/leetcode-js-88-merge-sorted-array/