剑指offer全集详解python版——合并两个有序链表

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。

思路：

谁小加谁，没了就把另一个全补在后面。

代码：

# -*- coding:utf-8 -*-
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class Solution:
    # 返回合并后列表
    def Merge(self, pHead1, pHead2):
        # write code here
        mergeHead = ListNode(90)
        p = mergeHead
        while pHead1 and pHead2:
            if pHead1.val >= pHead2.val:
                mergeHead.next = pHead2
                pHead2 = pHead2.next
            else:
                mergeHead.next = pHead1
                pHead1 = pHead1.next
                  
            mergeHead = mergeHead.next
        if pHead1:
            mergeHead.next = pHead1
        elif pHead2:
            mergeHead.next = pHead2
        return p.next