python 实现线性链表（单链表）--增加合并链表算法

初学python，拿数据结构中的线性链表存储结构练练手，理论比较简单，直接上代码。

#!/usr/bin/python

# Author: Hui
# Date: 2017-10-13

# 结点类，
class Node:

def __init__(self, data):    self.data = data            # 数据域    self.next = None            # 指针域def get_data(self):    return self.data

# 链表类
class List:

def __init__(self, head):    self.head = head            # 默认初始化头结点def is_empty(self):         # 空链表判断    return self.get_len() == 0def get_len(self):          # 返回链表长度    length = 0    temp = self.head    while temp is not None:        length += 1        temp = temp.next    return lengthdef append(self, node):         # 追加结点（链表尾部追加）    temp = self.head    while temp.next is not None:        temp = temp.next    temp.next = nodedef delete(self, index):           # 删除结点    if index < 1 or index > self.get_len():        print "给定位置不合理"        return    if index == 1:        self.head = self.head.next        return    temp = self.head    cur_pos = 0    while temp is not None:        cur_pos += 1        if cur_pos == index-1:            temp.next = temp.next.next        temp = temp.nextdef insert(self, pos, node):         # 插入结点    if pos < 1 or pos > self.get_len():        print "插入结点位置不合理..."        return    temp = self.head    cur_pos = 0    while temp is not Node:        cur_pos += 1        if cur_pos == pos-1:            node.next = temp.next            temp.next =node            break        temp = temp.nextdef reverse(self, head):          # 反转链表    if head is None and head.next is None:        return head    pre = head    cur = head.next    while cur is not None:        temp = cur.next        cur.next = pre        pre = cur        cur = temp    head.next = None    return predef print_list(self, head):           # 打印链表    init_data = []    while head is not None:        init_data.append(head.get_data())        head = head.next    return init_dataif __name__ == '__main__':    head = Node("head")    list = List(head)    print '初始化头结点：\t', list.print_list(head)    for i in range(1, 10):        node = Node(i)        list.append(node)    print '链表添加元素：\t', list.print_list(head)    print '链表是否空：\t', list.is_empty()    print '链表长度：\t', list.get_len()    list.delete(9)    print '删除第9个元素:\t',list.print_list(head)    node = Node("insert")    list.insert(3, node)    print '第3个位置插入‘insert’字符串 :\t', list.print_list(head)    head = list.reverse(head)    print '链表反转：', list.print_list(head)

执行结果：
初始化头结点： [‘head’]
链表添加元素： [‘head’, 1, 2, 3, 4, 5, 6, 7, 8, 9]
链表是否空： False
链表长度： 10
删除第9个元素: [‘head’, 1, 2, 3, 4, 5, 6, 7, 9]
第3个位置插入‘insert’字符串 : [‘head’, 1, ‘insert’, 2, 3, 4, 5, 6, 7, 9]
链表反转： [9, 7, 6, 5, 4, 3, 2, ‘insert’, 1, ‘head’]

————————-附加算法：要求合并两个有序链表，要求和并后依然有序—————————-

headA = Node(0)headB = Node(0)listA = List(headA)listB = List(headB)for i in range(10, 40, 5):    node = Node(i)    listA.append(node)for i in range(5, 30, 6):    node = Node(i)    listB.append(node)print "链表A：", listA.print_list(headA), "链表B：", listB.print_list(headB)def merge_list(headA, headB):  # 合并两个有序链表，要求合并后仍然有序    if headA.get_data() > headB.get_data():       headC = Node(headB.get_data())       headC.next = Node(headA.get_data())    else:        headC = Node(headA.get_data())        headC.next = Node(headB.get_data())    temp = headC.next    while headA.next is not None and headB.next is not None:        if headA.next.get_data() > headB.next.get_data():            temp.next = Node(headB.next.get_data())            headB = headB.next        else:            temp.next = Node(headA.next.get_data())            headA = headA.next        temp = temp.next    temp.next = headA.next if headA.next else headB.next  #把剩余非空链表，链接到C中    return headCafter_merge_head = merge_list(headA, headB)listC = List(after_merge_head)print "合并后：", listC.print_list(after_merge_head)

执行结果：
链表A： [0, 10, 15, 20, 25, 30, 35] 链表B： [0, 5, 11, 17, 23, 29]
合并后： [0, 0, 5, 10, 11, 15, 17, 20, 23, 25, 29, 25, 30, 35]

——————————-附加完———————————————————————————————–