LeetCode | Add Two Numbers

题目连接：https://leetcode-cn.com/problems/add-two-numbers/

题目：

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

思路：
思路非常简单，利用两个指针分别遍历两个链表，并且用一个变量表示是否有进位。某个链表遍历结束之后再将另一个链表连接在结果链表之后即可，若最后有进位需要添加一位。

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        int jw =0;
        ListNode result = new ListNode(0);
        ListNode re = result;
        while(l1!=null || l2!=null){
            int va1 = 0;
            if(l1 != null){
                va1 = l1.val;
                l1 = l1.next;
            }
            
            int va2 = 0;
            if(l2 != null){
                va2 = l2.val;
                l2 = l2.next;
            }
            
            int tmp = va1 + va2 + jw;
            re.next = new ListNode(tmp%10);
            jw = tmp/10;
            re = re.next;
        }
        
        if(jw!=0){
            re.next = new ListNode(jw);
        }
        return result.next;
    }
}

参考：https://blog.csdn.net/lanxu_yy/article/details/11688591