LeetCode-2:Add Two Numbers

2.Add Two Numbers

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

题意：给出两个非负整数的非空链表。数字以相反的顺序存储，它们的每个节点都包含一个数字。添加两个数字，并将其作为链接列表返回。

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { val = x; } * } */public class Solution {    //题目没什么难的，就是实现两个链表对应为的叠加，主要要注意进位问题    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {        ListNode t1=l1;        ListNode t2=l2;        ListNode tt=new ListNode(0);        ListNode cur=tt;        int sum=0;        while(t1!=null||t2!=null){                        if(t1!=null){                sum+=t1.val;                t1=t1.next;            }                        if(t2!=null){                sum+=t2.val;                t2=t2.next;            }                        cur.next=new ListNode(sum%10);            cur=cur.next;            sum=sum/10;        }        //判断最后sum的值是否为零        if(sum!=0){            cur.next=new ListNode(sum);        }        return tt.next;    }}