两数相加 Add Two Numbers [M]

题目：

https://leetcode.cn/problems/add-two-numbers/description/?favorite=2cktkvj

讲解

https://www.youtube.com/watch?v=wgFPrzTjm7s&ab_channel=NeetCode

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode dummy = new ListNode();
        ListNode cur = dummy;
        int carry = 0;
        while(l1 != null || l2 != null || carry !=0){
            int v1 = l1 != null ? l1.val : 0;
            int v2 = l2 != null ? l2.val : 0;
            int v = v1 + v2 + carry;
            carry = v / 10;
            v %=  10;
            cur.next = new ListNode(v); 
            cur = cur.next;
            if(l1 != null)l1 = l1.next;
            if(l2 != null)l2 = l2.next;
        }
        return dummy.next;
    }