菜鸟写LEETCODE题解

LEETCODE原题如下：

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)
Output: 7 -> 0 -> 8

解答：

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { val = x; } * } */ //对节点的操作需要用一个节点去记录链表头节点的地址。 //也需要一个操作节点，去对链表中的节点进行操作。public class Solution {    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {        ListNode out=new ListNode(0);        ListNode node=out;        int sum=0;        while(l1!=null||l2!=null){            sum=sum/10;         if(l1!=null){             sum+=l1.val;             l1=l1.next;         }         if(l2!=null){             sum+=l2.val;             l2=l2.next;         }         node.next=new ListNode(sum%10);//把新的数据连接入链表         node=node.next;        }        if (sum / 10 == 1)         node.next = new ListNode(1);        return out.next;    }}