DAY2：leetcode #2 Add Two Numbers

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

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

class Solution(object):
def addTwoNumbers(self, l1, l2):
"""
:type l1: ListNode
:type l2: ListNode
:rtype: ListNode
"""
c = 0
r2 = None
result = []
while True:
if l1 != None and l2 != None:
y1 = l1.val + l2.val + c
l1 = l1.next
l2 = l2.next
elif l1 == None and l2 != None:
y1 = l2.val + c
l2 = l2.next
elif l1 != None and l2 == None:
y1 = l1.val + c
l1 = l1.next
elif l1 == None and l2 == None and c != 0:
y1 = c
else:
break
if y1 > 9:
y1 = y1 % 10
c = 1
else:
c = 0
result.append(y1)
for i in result[::-1]:
r1 = ListNode(i)
r1.next = r2
r2 = r1
return r1

没啥好说的，逻辑对了就通过了