貌似不需要p1 p1变量

来源：5-4 LeetCode：2. 两数相加

背着行囊独自流浪

2021-03-27

var addTwoNumbers = function(l1, l2) {
    const dummyHead = new ListNode(0);
    let p = dummyHead;
    let carry = 0;

    while (l1 || l2) {
        const v1 = l1 ? l1.val : 0;
        const v2 = l2 ? l2.val : 0;
        const v3 = v1 + v2 + carry;
        p.next = new ListNode(v3 % 10);
        carry = Math.floor(v3 / 10);

        if (l1) {
            l1 = l1.next;
        }
        if (l2) {
            l2 = l2.next;
        }

        p = p.next;
    }

    if (carry) {
        p.next = new ListNode(carry);
    }

    return dummyHead.next;
};