linked list

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 contains a single digit. Add the two numbers and return the sum as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

# Definition for singly-linked list.
# 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=cur=ListNode(0)
        c=0
        while l1 or l2 or c:
            if l1:
                c+=l1.val
                l1=l1.next
            if l2:
                c+=l2.val
                l2=l2.next
            cur.next=ListNode(c%10)
            cur=cur.next
            c//=10
        return dummy.next