Add Two Numbers

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

leetcode的第二道题目，大致思路就是从前面加到后面，如果有进位的话存储一下。

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