python链表操作

python的链表操作

class Node():
    def __init__(self, value=None, next=None):
        self.__value = value
        self.__next = next
        
def getValue(self):
    return self.__value

def getNext(self):
    return self.__next

def setValue(self, newValue):
    self.__value = newValue

def setNext(self, nexNext):
    self.__next = nexNext
    
class Link():
    def __init__(self):
        self.__head = Node()             #头结点，不存放元素，哨兵节点
        self.__tail = None
        self.__length = 0

def isEmpty(self):
    '''
    判断链表是否为空
    :return:
    '''
    return self.__head.getNext() == None

def add(self, value):
    '''
    头插法插入元素
    :param value:
    :return:
    '''
    newnode = Node(value, None)
    newnode.setNext(self.__head.getNext())
    self.__head.setNext(newnode)
    
def append(self, value):
    '''
    尾插法插入元素
    :param value:
    :return:
    '''
    newnode = Node(value)
    if self.isEmpty():
        self.__head.setNext(newnode)
    else:
        current = self.__head.getNext()
        while current.getNext() != None:
            current = current.getNext()
        current.setNext(newnode)
        
def search(self, value):
    '''
    查找链表中是否含有该元素
    :param value:
    :return:
    '''
    current = self.__head
    foundvalue = False
    while current != None and not foundvalue:
        if current.getValue() == value:
            foundvalue = True
        else:
            current = current.getNext()
    return foundvalue

def index(self, value):
    '''
    查找该元素在链表中的下标位置，
    若没有则返回None
    :param value:
    :return:
    '''
    current = self._head
    count = 0
    found = None
    while current != None and not found:
        count += 1
        if current.getValue() == value:
            return count
    return None

def print(self):
    '''
    打印链表元素
    :return:
    '''
    current = self.__head.getNext()
    while current != None:
        print(current.getValue())
        current = current.getNext()

def delete(self, value):
    '''
    删除指定元素
    :param value:
    :return:
    '''
    current = self._head
    while current.getNext() != None and current.getNext().getValue() != value:
        current = current.getNext()
    if current.getNext() == None:
        return 0                    #链表中无此元素，删除失败
    else:
        r = current.getNext()
        current.setNext(r.getNext())
        del r
        return 1