【leetcode刷题笔记】Add Two Numbers

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.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

 1 /**
 2  * Definition for singly-linked list.
 3  * public class ListNode {
 4  *     int val;
 5  *     ListNode next;
 6  *     ListNode(int x) {
 7  *         val = x;
 8  *         next = null;
 9  *     }
10  * }
11  */
12 public class Solution {
13     public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
14         if(l1 == null && l2 == null)
15             return null;
16
17         ListNode kepeler = new ListNode(0);
18         ListNode head = kepeler;
19         int carries = 0;
20
21         while(l1 != null && l2 != null){
22             int sum = carries + l1.val + l2.val;
23             carries = sum/10;
24             kepeler.next = new ListNode(sum%10);
25             kepeler = kepeler.next;
26             l1 = l1.next;
27             l2 = l2.next;
28         }
29
30         while(l1 != null){
31             int sum = carries + l1.val;
32             carries = sum/10;
33             kepeler.next = new ListNode(sum%10);
34             l1 = l1.next;
35             kepeler = kepeler.next;
36         }
37
38         while(l2 != null){
39             int sum = carries + l2.val;
40             carries = sum/10;
41             kepeler.next = new ListNode(sum%10);
42             l2 = l2.next;
43             kepeler = kepeler.next;
44         }
45
46         if(carries != 0)
47             kepeler.next = new ListNode(carries);
48
49         return head.next;
50     }
51 }

【leetcode刷题笔记】Add Two Numbers