插入排序(Insertion sort)

• 算法描述：
  the list is divided into two sublists: sorted and unsorted.

Step1: move the first element of the unsorted list into the sorted list in the proper place.

Step2: repeat this process on the resulting list

• 适用：list和linked list

• 时间复杂度：the time required is O(n^2), it is proportional to n^2, where n is the number of data items in the array

• 稳定性：stable