# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
#
# 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
#
# 
# @param pHead1 ListNode类 
# @param pHead2 ListNode类 
# @return ListNode类
#
class Solution:
    def Merge(self , pHead1: ListNode, pHead2: ListNode) -> ListNode:
        # write code here
        if not pHead1 or not pHead2:
            return pHead1 or pHead2
        if pHead1.val>pHead2.val:  # 表1的值大于表2的值
            pHead2.next=self.Merge(pHead1, pHead2.next)
            return pHead2
        else:
            pHead1.next=self.Merge(pHead1.next,pHead2)
            return pHead1

​list1[0]+merge(list1[1],list2[0]) ​list1[0]<list2[0]

list2[0]+merge(list1[0],list2[1]) othervise​