剑指offer-合并两个排序链表16

题目描述

输入两个单调递增的链表，输出两个链表合成后的链表，当然我们需要合成后的链表满足单调不减规则。

 class Solution:
     # 返回合并后列表
     def Merge(self, pHead1, pHead2):
         # write code here
         if pHead1==None:
             return pHead2
         if pHead2==None:
             return pHead1
         head=ListNode(-1)
         head.next=None
         root=head
         while pHead1 is not None and pHead2 is not None:
             if pHead1.val<pHead2.val:
                 head.next=pHead1
                 head=pHead1
                 pHead1=pHead1.next
             else:
                 head.next=pHead2
                 head=pHead2
                 pHead2=pHead2.next
         if pHead1 is None:
             head.next=pHead2
         else:
             head.next=pHead1
         return root.next