LeetCode 21. 合并两个有序链表
# Definition for singly-linked list. # class ListNode: # def __init__(self, x): # self.val = x # self.next = None class Solution: def mergeTwoLists(self, l1, l2): prehead = ListNode() prev = prehead while l1 and l2: if l1.val <= l2.val: prev.next = l1 l1 = l1.next else: prev.next = l2 l2 = l2.next prev = prev.next # 合并后 l1 和 l2 最多只有一个还未被合并完,我们直接将链表末尾指向未合并完的链表即可 prev.next = l1 if l1 is not None else l2 return prehead.next