[Leetcode] 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

Solution：

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode result=new ListNode(-1);
        ListNode cur=result;
        int carry=0;
        while(l1!=null&&l2!=null){
            int temp=l1.val+l2.val+carry;
            carry=temp/10;
            temp%=10;
            cur.next=new ListNode(temp);
            cur=cur.next;
            l1=l1.next;
            l2=l2.next;
        }
        while(l1!=null){
            int temp=l1.val+carry;
            carry=temp/10;
            temp%=10;
            cur.next=new ListNode(temp);
            cur=cur.next;
            l1=l1.next;
        }
        while(l2!=null){
            int temp=l2.val+carry;
            carry=temp/10;
            temp%=10;
            cur.next=new ListNode(temp);
            cur=cur.next;
            l2=l2.next;
        }
        if(carry!=0){
            cur.next=new ListNode(carry);
        }
        return result.next;
    }
}