Python笔记之 的链表基本操作

#!/usr/bin/python
# -*- coding: utf-8 -*-

# 链表的话就有data存放数据，next指向下一个data
class Node(object):  # 节点类
    def __init__(self, data):
        self.data = data
        self.pnext = None

    def __repr__(self):  # 用来打印节点
        return str(self.data)


class LinkTable(object):  # 链表类
    def __init__(self):
        self.head = None
        self.length = 0

    def isEmpty(self):
        return self.length == 0

    def append(self, node_data):  # 这是用来创建链表的,(在链表末添加对象)
        if isinstance(node_data, Node):
            pass
        else:
            node_data = Node(node_data)  # 把node_data封装成一个带有一个pnext=None的节点对象

        if self.isEmpty():  # 如果链表为空
            self.head = node_data
        else:
            node = self.head
            while node.pnext:  # 通过遍历找到最末端节点，最末端节点的pnext一定是None
                node = node.pnext
            node.pnext = node_data
        self.length += 1

    def insert(self, node_data, index):
        if type(index) is int:
            if isinstance(node_data, Node):
                pass
            else:
                node_data = Node(node_data)
            if self.isEmpty():
                self.head = node_data
                print u'此为空链表，只能插入在表头！'
                return
            elif index > self.length or index < 0:
                print u'索引越界！'
                return
            else:
                if index == 0:
                    node_data.pnext = self.head
                    self.head = node_data
                else:
                    i = 0
                    node = self.head
                    while i < index-1:
                        node = node.pnext
                        i += 1
                    node_data.pnext = node.pnext
                    node.pnext = node_data
                self.length += 1
                return

        else:
            print u'索引值非整型数字！'
            return

    def delete(self, index):
        if type(index) is int:

            if self.isEmpty():
                print u'此为空链表，无法删除！'
                return
            elif index > self.length or index < 0:
                print u'索引越界！'
                return
            else:
                if index == 0:
                    self.head = self.head.pnext
                else:
                    i = 0
                    node = self.head
                    while i < index-1:
                       node = node.pnext
                       i += 1
                    node.pnext = node.pnext.pnext
                self.length -= 1
            return
        else:
            print u'索引值非整型数字！'
            return

    def update(self, new_data, index):
        if type(index) is int:
            if isinstance(new_data, Node):
                pass
            else:
                new_data = Node(new_data)
            if self.isEmpty():
                print u'此为空链表，无法更新！'
                return
            elif index > self.length or index < 0:
                print u'索引越界！'
                return
            else:
                if index == 0:
                    new_data.pnext = self.head.pnext
                    self.head = new_data
                    return
                else:
                    i = 0
                    node = self.head
                    while i < index-1:
                        node = node.pnext  # 找到需要更新点
                        i += 1
                    new_data.pnext = node.pnext.pnext
                    node.pnext = new_data
                    return
        else:
            print u'索引值非整型数字！'
            return

    def get_value(self, index):
        if type(index) is int:
            if self.isEmpty():
                print u'此为空链表，无法取值！'
                return
            elif index > self.length or index < 0:
                print u'索引越界！'
                return
            else:
                i = 0
                node = self.head
                while i < index:
                    node = node.pnext
                    i += 1
                if node:
                    return node.data
                else:
                    return

        else:
            print u'索引值非整型数字！'
            return
    def get_all_value(self):
        i = 0
        node = self.head
        while i < self.length:
            yield node.data
            node = node.pnext
            i += 1
    def clear(self):
        '''
        # 就是重新初始化一下
        :return: 
        '''
        self.head = None
        self.length = 0
        print u'链表已经清空！'



list_table = LinkTable()
for i in xrange(10):
    list_table.append(i)
#print list_table.get_value(9)
#list_table.update(100,9)
#print list_table.get_value(9)
#list_table.delete(9)
#print list_table.get_value(9)
for data in list_table.get_all_value():
    print data
list_table.insert(100,9)
print '----------------'
for data in list_table.get_all_value():
    print data