【LeetCode】 002. Add Two Number

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

/** * 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) {        int sum = 0;        ListNode res = new ListNode(0);        ListNode temp = res;        while (l1 != null || l2 != null) {            sum /= 10;            if (l1 != null) {                sum += l1.val;                l1 = l1.next;            }            if (l2 != null) {                sum += l2.val;                l2 = l2.next;            }            temp.next = new ListNode(sum % 10);            temp = temp.next;        }        if (sum / 10 == 1) {            temp.next = new ListNode(1);        }        return res.next;    }}