一、题目——Add Two Numbers
You are given twonon-emptylinked 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)
Output:7 -> 0 -> 8
二、分析
给了两个链表，然后每个链表的每个节点代表一位。就是 2->4->3 为 243的意思。然后做加法。那么我们可以先翻转链表。然后循环一位一位加，类似整数加法一样。
三、代码
