002 Add Two Numbers

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 contain a single digit. Add the two numbers and return it as a linked list.

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

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

# Definition for singly-linked list.# class ListNode(object):#     def __init__(self, x):#         self.val = x#         self.next = Noneclass Solution(object):    def addTwoNumbers(self, l1, l2):        """        :type l1: ListNode        :type l2: ListNode        :rtype: ListNode        """        carry=0        root=n=ListNode(0)        while l1 or l2 or carry:            v1=v2=0            if l1:                v1=l1.val                l1=l1.next            if l2:                v2=l2.val                l2=l2.next            n.next=ListNode((v1+v2+carry)%10)            n=n.next            carry=(v1+v2+carry)//10        return root.next