Leetcode第2题

链接：https://leetcode.com/problems/add-two-numbers/
You are given two non-empty linked 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 linked 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 class ListNode {
    int val;
    ListNode next;

    ListNode(int x) {
        val = x;
    }
}

    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode result = new ListNode(0);
        ListNode p = l1, q = l2, current = result;
        int carry = 0;
        while (!(p == null && q == null)) {
            int x = (p != null) ? p.val : 0;
            int y = (q != null) ? q.val : 0;
            int sum = carry + x + y;
            carry = sum / 10;
            current.next = new ListNode(sum % 10);
            current = current.next;
            if (p != null)
                p = p.next;
            if (q != null)
                q = q.next;
        }
        if (carry > 0) {
            current.next = new ListNode(carry);
        }
        return result.next;
    }