劍指offer 之 合併兩個排序的鏈表

# -*- coding:utf-8 -*-

'''
面試題17：合併兩個排序的鏈表
輸入兩個單調遞增的鏈表，輸出兩個鏈表合成後的鏈表，當然我們需要合成後的鏈表滿足單調不減規則。
基本思路：遞歸
'''

class ListNode:
    def __init__(self, x):
        self.val = x
        self.next = None

class Solution:
    # 返回合併後列表
    def Merge(self, pHead1, pHead2):
        # write code here
        if pHead1 == None:
        	return pHead2
        elif pHead2 == None:
        	return pHead1

        pMergedHead = None
        if pHead1.val < pHead2.val:
        	pMergedHead = pHead1
        	pMergedHead.next = self.Merge(pHead1.next, pHead2)
        else:
        	pMergedHead = pHead2
        	pMergedHead.next = self.Merge(pHead1, pHead2.next)
        return pMergedHead

node1 = ListNode(1)
node2 = ListNode(3)
node3 = ListNode(5)
node1.next = node2
node2.next = node3

node4 = ListNode(2)
node5 = ListNode(4)
node6 = ListNode(6)
node4.next = node5
node5.next = node6

S = Solution()
S.Merge(node1, node4)
print(node3.next.val)