2_addTwoNumbers_modify.py

# 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
        """
        carry = 0
        res = n = ListNode(0)
        while l1 or l2 or carry:
            if l1:
                carry += l1.val
                l1 = l1.next
            if l2:
                carry += l2.val
                l2 = l2.next
            carry, val = divmod(carry, 10)
            n.next = n = ListNode(val)
        return res.next


# For test
solution = Solution()
l1 = ListNode(2)
l1.next = ListNode(4)
(l1.next).next = ListNode(3)

l2 = ListNode(5)
l2.next = ListNode(6)
(l2.next).next = ListNode(4)

l4 = solution.addTwoNumbers(l1,l2)
print l4