题目：

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

 

代码：oj测试通过 Runtime: 171 ms

1 # Definition for singly-linked list. 2 # class ListNode: 3 #     def __init__(self, x): 4 #         self.val = x 5 #         self.next = None 6  7 class Solution: 8     # @return a ListNode 9     def addTwoNumbers(self, l1, l2):10         if l1 is None:11             return l212         if l2 is None:13             return l114         15         dummyhead = ListNode(0)16         p = ListNode(0)17         dummyhead.next = p18         19         jinwei = 020         while l1 is not None and l2 is not None:21             curr_total = l1.val + l2.val + jinwei22             l1 = l1.next23             l2 = l2.next24             curr_digit = curr_total % 1025             jinwei = curr_total / 1026             curr_node = ListNode(curr_digit)27             p.next = curr_node28             p = p.next29             30         if l1 is not None:31             while l1 is not None:32                 curr_total = l1.val + jinwei33                 l1 = l1.next34                 curr_digit = curr_total % 1035                 jinwei = curr_total / 1036                 curr_node = ListNode(curr_digit)37                 p.next = curr_node38                 p = p.next39         if l2 is not None:40             while l2 is not None:41                 curr_total = l2.val + jinwei42                 l2 = l2.next43                 curr_digit = curr_total % 1044                 jinwei = curr_total / 1045                 curr_node = ListNode(curr_digit)46                 p.next = curr_node47                 p = p.next48         49         if jinwei == 1:50             curr_node = ListNode(1)51             p.next = curr_node52         53         return dummyhead.next.next

思路：

就是加法运算 注意两条链表上所有值计算过后 是否有进位；如果有进位 需要再处理一下。