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



In [1]:

    
class ListNode(object):
    def __init__(self, x):
        self.val = x
        self.next = None



In [63]:

    
class Solution(object):
    def addTwoNumbers(self, l1, l2):
        """
        1、对象引用的复制，必须引用同一个对象，才能保证当前引用的对象
        2、考虑进位以及低位数加高位数的情况
        :type l1: ListNode
        :type l2: ListNode
        :rtype: ListNode
        """
        ans = p = ListNode(0)
        carry = 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
            carry, p.val = divmod(v1 + v2 + carry, 10)
            if l1 or l2 or carry:
                p.next = ListNode(0)
                p = p.next
        return ans



In [60]:

    
l1 = ListNode(2)
l1.next = ListNode(4)
l1.next.next = ListNode(3)
l2 = ListNode(5)
l2.next = ListNode(6)
l2.next.next = ListNode(4)



In [61]:

    
l = Solution().addTwoNumbers(l1, l2)



In [62]:

    
while l:
    print (l.val)
    l = l.next



In [ ]: