You are given two linked lists representing two non-negative numbers. 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.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
This problem is marked as Medium.
1 # Definition for singly-linked list.
2 # class ListNode(object):
3 # def __init__(self, x):
4 # self.val = x
5 # self.next = None
6
7 class Solution(object):
8 def addTwoNumbers(self, l1, l2):
9 """
10 :type l1: ListNode
11 :type l2: ListNode
12 :rtype: ListNode
13 """
14 output = ListNode(0)
15 p = output
16
17 while l1 or l2:
18 v1 = l1.val if l1 else 0
19 v2 = l2.val if l2 else 0
20 s = v1 + v2 + p.val
21 digit = s % 10
22 rem = s // 10
23 p.val = digit
24 l1 = l1.next if l1 else l1
25 l2 = l2.next if l2 else l2
26 if l1 or l2 or rem > 0:
27 p.next = ListNode(rem)
28 p = p.next
29 return output