将两个有序链表合并为一个新的有序链表并返回。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
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution:
def mergeTwoLists(self, l1, l2):
"""
:type l1: ListNode
:type l2: ListNode
:rtype: ListNode
"""
dummy = ListNode(-1)
dummy.next = l2#将l1插入l2中
temp = dummy
temp1, temp2 = l1, l2
while temp2 != None and temp1 != None:#当l1和l2都非空的时候
if temp2.val > temp1.val:
temp.next = temp1
temp1 = temp1.next
temp = temp.next
temp.next =temp2
else:
temp = temp.next
temp2 = temp2.next
if temp2 == None:
temp.next = temp1
return dummy.next