LeetCode2 Add Two Numbers

You are given two non-empty ed 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 ed list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Example:

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode dummy = new ListNode(0);
        ListNode node = dummy;
        int carry = 0;
        int k1 = 0, k2 = 0 , newval = 0;
        while(l1 != null || l2 != null || carry != 0){
            k1 = l1 == null ? 0 : l1.val;
            k2 = l2 == null ? 0 : l2.val;
            newval = (k1 + k2 + carry) % 10;
            ListNode newNode = new ListNode(newval);
            node.next = newNode;
            node = node.next;
            carry = (k1 + k2 + carry) / 10;
            if(l1 != null) l1 = l1.next;
            if(l2 != null) l2 = l2.next;
        }
        return dummy.next;
    }