給出兩個 非空 的連結串列用來表示兩個非負的整數。其中，它們各自的位數是按照 逆序 的方式儲存的，並且它們的每個節點只能儲存 一位 數字。
如果，我們將這兩個數相加起來，則會返回一個新的連結串列來表示它們的和。
您可以假設除了數字 0 之外，這兩個數都不會以 0 開頭。
 
 
示例：
輸入：(2 -> 4 -> 3) + (5 -> 6 -> 4)
輸出：7 -> 0 -> 8
原因：342 + 465 = 807

#!/usr/bin/python3
# -*- coding:utf-8 -*-
 
 
# Definition for
 
 singly-linked list.
class ListNode:
     def __init__(self, x):
         self.val = x
         self.next = None
 
 
class Solution:
    def addTwoNumbers(self, l1: ListNode, l2: ListNode):
        re = ListNode(0)
        r=re
        carry=0
        while(l1 or l2):
            x= l1.val if l1 else 0
 

            y= l2.val if l2 else 0
            s=carry+x+y
            carry=s//10
            r.next=ListNode(s%10)
            r=r.next
            if(l1!=None):l1=l1.next
            if(l2!=None):l2=l2.next
        if(carry>0):
            r.next=ListNode(1)
        return re.next
 
 
obj=Solution()
 
 
node1
 
=ListNode(1)
node2=ListNode(2)
node3=ListNode(3)
node1.next=node2
node2.next=node3
 
 
node11=ListNode(2)
node12=ListNode(3)
node13=ListNode(4)
node11.next=node12
node12.next=node13
 
 
res=obj.addTwoNumbers(node1,node11)
while(res):
    print(res.val)
    res=res.next

macname@MacdeMacBook-Pro py % python3 cccccc.py
3
5
7
macname@MacdeMacBook-Pro py %

#!/usr/bin/python3.7
# -*- coding:utf-8 -*-
 
 
# Definition for singly-linked list.
class ListNode:
     def __init__(self, x):
         self.val = x
         self.next = None
 
 
class Solution:
    def __init__(self):
        self.num1=""
        self.num2=""
    def addTwoNumbers(self, l1: ListNode, l2: ListNode):
        while(l1):
            self.num1+=str(l1.val)
            l1=l1.next
        while(l2):
            self.num2+=str(l2.val)
            l2=l2.next
 
 
        sum=int(self.num1[::-1])+int(self.num2[::-1])
 
 
        new = ListNode(0)
        head = new
        for number in str(sum)[::-1]:
            head.next = ListNode(int(number))
            head = head.next
        return new.next
 
 
obj=Solution()
 
 
node1=ListNode(2)
node2=ListNode(4)
node3=ListNode(3)
node1.next=node2
node2.next=node3
 
 
node11=ListNode(5)
node12=ListNode(6)
node13=ListNode(4)
node11.next=node12
node12.next=node13
 
 
res=obj.addTwoNumbers(node1,node11)
 
 
while(res):
    print(res.val)
    res=res.next

outputs

macname@MacdeMacBook-Pro py % python3 cccccc.py
7
0
8
macname@MacdeMacBook-Pro py %