[电脑网络]Add two numbers

The leetcode question "adding two numbers" (https://oj.leetcode.com/problems/add-two-numbers/)  is a hard on for me. But I got to understand the concept of linked list and finally was able to manipulate it after finishing this question.

The Question.:

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

My solution can be found here.

The hard part is figuring out how to create new nodes and move to next node of the linked list. Once I got this the problem was not too hard to solve.