两数相加python

输入：l1 = [2,4,3], l2 = [5,6,4]
输出：[7,0,8]
解释：342 + 465 = 807.

class ListNode:
    def __init__(self,val=0,next=None):
        self.val = val
        self.next = next
         
class Solution:
    def addTwoNumbers(self,l1:ListNode,l2:ListNode)->ListNode:
        dummy = p = ListNode(None)
        s = 0
        while l1 or l2 or s!=0:
            s += (l1.val if l1 else 0)+(l2.val if l2 else 0)
            p.next = ListNode( s % 10)
            p = p.next
            if l1: l1 = l1.next
            if l2: l2 = l2.next
            s = s//10
        return dummy.next