"""
两数相加
"""
from typing import List, Optional


class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next


class Solution:
    def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]:
        """
        链表遍历
        :param l1:
        :param l2:
        :return:
        """
        res = ListNode(0)
        cur = res
        carry = 0
        while l1 or l2:
            x = l1.val if l1 else 0
            y = l2.val if l2 else 0
            s = x + y + carry
            carry = s // 10
            cur.next = ListNode(s % 10)
            cur = cur.next
            if l1:
                l1 = l1.next
            if l2:
                l2 = l2.next
        if carry:
            cur.next = ListNode(carry)
        return res.next


if __name__ == '__main__':
    l1 = ListNode(2)
    l1.next = ListNode(4)
    l1.next.next = ListNode(3)

    l2 = ListNode(5)
    l2.next = ListNode(6)
    l2.next.next = ListNode(4)
    result = Solution().addTwoNumbers(l1, l2)
    while result:
        print(result.val, end=' -> ')
        result = result.next