题目链接：https://leetcode-cn.com/problems/he-bing-liang-ge-pai-xu-de-lian-biao-lcof/
难度：简单

描述：
输入两个递增排序的链表，合并这两个链表并使新链表中的节点仍然是递增排序的。

题解

  1. # Definition for singly-linked list.
  2. # class ListNode:
  3. #     def __init__(self, x):
  4. #         self.val = x
  5. #         self.next = None
  7. class Solution:
  8.     def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:
  9.         dummy = ListNode(-1)
  10.         temp = dummy
  11.         p, q = l1, l2
  12.         while p and q:
  13.             if p.val < q.val:
  14.                 temp.next = p
  15.                 p = p.next
  16.             else:
  17.                 temp.next = q
  18.                 q = q.next
  19.             temp = temp.next
  21.         temp.next = p if p else q
  23.         return dummy.next