题目： 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. (认为也可以看做是有序数组的相加) Input: (2 -> 4 -> 3) + (5 -> 6 -> 4) Output: 7 -> 0 -> 8 使用什么语言实现思路都近似，此处用java实现。
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ public class Solution { public ListNode addTwoNumbers(ListNode l1, ListNode l2) { if(l1 == null && l2 == null) { return null; } ListNode lhead; ListNode l = new ListNode(0); lhead = l;//用于保存最初位置 int flag=0; while(l1!=null || l2!=null) { ListNode lnext = new ListNode(0);//每次运算保存于新添加的节点并接在后面 int a = l1==null?0:l1.val; int b = l2==null?0:l2.val; lnext.val = (a+b+flag)%10; flag = (a+b+flag)/10; l.next = lnext; l = l.next; l1 = l1==null?null:l1.next; l2 = l2==null?null:l2.next; } if(flag != 0) //如果还有进位，添加节点存入其中 { ListNode lnext = new ListNode(0); lnext.val = flag; l.next = lnext; lnext.next = null; } return lhead.next; } }