LeetCode 21. 合并两个有序链表 Merge Two Sorted Lists
Table of Contents
一、中文版
将两个升序链表合并为一个新的升序链表并返回。新链表是通过拼接给定的两个链表的所有节点组成的。
示例:
输入:1->2->4, 1->3->4
输出:1->1->2->3->4->4
二、英文版
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 来源:力扣(LeetCode) 链接:https://leetcode-cn.com/problems/merge-two-sorted-lists 著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。
三、My answer
# 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: dummy = ListNode(0) head = dummy while l1 and l2: if l1.val <= l2.val: head.next = l1 l1 = l1.next else: head.next = l2 l2 = l2.next head = head.next if l1: head.next = l1 if l2: head.next = l2 return dummy.next
四、解题报告
此题用来熟悉 Python 链表的写法很好。
从头开始遍历两个链表,比较两个头结点的大小,将小的放入结果链表中。
剩下没遍历结束的 l1 或 l2,就直接拼接在结果链表中即可。