"""
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.

Example:

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.
"""

# Definition for singly-linked list.
class ListNode(object):
  def __init__(self, x):
    self.val = x
    self.next = None

class Solution:
  def addTwoNumbers(self, l1, l2, c = 0):
    # Fill this in.
    s = ListNode(0)
    ret = s
    while l1 != None or l2 != None:
      x = l1.val if l1 != None else 0
      y = l2.val if l2 != None else 0
      s.next = ListNode((x+y+c)%10)
      s = s.next
      c = (x+y+c)/10
      if l1 != None: l1 = l1.next
      if l2 != None: l2 = l2.next
    if c > 0: s.next = ListNode(c)
    return ret.next

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,
  result = result.next
# 7 0 8
