1.Description
You are given two non-empty linked lists representing two non-negative integers. 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.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
2.How to deal with
值得注意的是开始建立的是指向头结点的前一个节点的指针，最后返回的是这个指针指向的节点的下一个节点。