• 分類：LinkedList

• 考察知識點：LinkedList

• 最優(yōu)解時間復(fù)雜度：**O(n) **

2. Add Two Numbers

1. 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.

   Example:

   Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
   Output: 7 -> 0 -> 8
   Explanation: 342 + 465 = 807.
   

代碼：

解法:

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

class Solution:
    def addTwoNumbers(self, l1, l2):
        res=ListNode(0)
        resp=res
        sum_=0
        p1=l1
        p2=l2
        while(p1!=None or p2!=None):
            if(p1!=None):
                sum_+=p1.val
                p1=p1.next
            if(p2!=None):
                sum_+=p2.val
                p2=p2.next
            resp.next=ListNode(sum_%10)
            sum_//=10
            resp=resp.next
        if sum_==1:
            resp.next=ListNode(1)
            
        return res.next

討論：

1.太簡單的幾乎不用懂腦子

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