leetCode练题——21. Merge Two Sorted Lists（照搬大神做法）

1、题目

21. Merge Two Sorted Lists

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

Example:

Input: 1->2->4, 1->3->4
Output: 1->1->2->3->4->4

2、我的解答

 # -*- coding: utf-8 -*-
 # @Time    : 2020/2/1 18:30
 # @Author  : SmartCat0929
 # @Email   : 1027699719@qq.com
 # @Link    : https://github.com/SmartCat0929
 # @Site    :
 # @File    : 21.Merge Two Sorted Lists.py

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

 class Solution:
     def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:
         head = l3 = ListNode(0)
         while(l1 is not None and l2 is not None):
             if l1.val <=l2.val:
                 l3.next = ListNode(l1.val)
                 l3 = l3.next
                 l1 = l1.next
             else:
                 l3.next = ListNode(l2.val)
                 l3 = l3.next
                 l2 = l2.next
         while l1:
             l3.next = ListNode(l1.val)
             l3 = l3.next
             l1 = l1.next
         while l2:
             l3.next = ListNode(l2.val)
             l3 = l3.next
             l2 = l2.next
         return head.next

 h1 = ListNode(1)
 h1.next = ListNode(2)
 h1.next.next = ListNode(4)

 h2 = ListNode(1)
 h2.next = ListNode(3)
 h2.next.next = ListNode(4)

 h = Solution().mergeTwoLists(h1, h2)
 while h is not None:
     print(h.val, end="->")
     h = h.next