无序链表LinkList Python 实现

'''
: MasonHu
: 2020/01/01
'''


# 节点实现, 链表中的每个数据元素
class Node:
    # 初始化节点
    def __init__(self, init_data):
        self.data = init_data
        self.next = None

    # 获取当前节点存放数据
    def get_data(self):
        return self.data

    # 设置当前节点数据
    def set_data(self, new_data):
        self.data = new_data

    # 获取下个节点
    def get_next(self):
        return self.next

    # 设置下一个节点
    def set_next(self, new_next):
        self.next = new_next



'''
无序链表
链表必须要有对 第一个节点 的引用.
所以设定一个 链表头 self.head, 保存对第一个节点的引用.
空链表的head设定为None.
注意! LinkList对象本身不保存数据(数据项), 数据保存在节点中
其中包含的head只是对首个节点的引用(地址,指针)
'''
class LinkList:
    # 初始化链表, 设定head为空(None)
    def __init__(self):
        self.head = None

    # 判断链表是否为空
    def is_empty(self):
        return self.head == None

    # 寻找
    def search(self, item):
        current = self.head
        found = False
        while current !=None and not found:
            if current.get_data() == item:
                found = True
            else:
                current = current.get_next()

    # 添加节点
    def add(self, item):
        temp = Node(item)
        temp.set_next(self.head)
        self.head = temp

    # 移除节点
    def remove(self, item):
        current = self.head
        previous = None
        found = False

        while not found:
            if current.get_data() == item:
                found = True
            else:
                previous = current
                current = current.get_next()

        if previous == None:
            self.head = current.get_next()
        else:
            previous.set_next(current.get_next())

    # 链表大小
    def size(self):
        current = self.head
        count = 0
        while current != None:
            current = current.get_next()
            count = count + 1
        return count


    # 链表尾部添加节点
    def append(self, item):
        pass

    # 链表尾部删除节点
    def pop(self, item):
        pass


    # 移除节点, 有问题
    def remove_(self, item):
        previous = None
        current = self.head
        while current != None:
            if  current.get_data() == item and previous==None:
                self.head = current.get_next()
            elif current.get_data() == item:
                previous.set_next(current.get_next())
            else:
                previous = current
                current = current.get_next()