数据结构之链表-python实现

class Node(object):
    def __init__(self, data):
        self.next = None
        self.data = data

    def setNext(self, newnext):
        self.next = newnext

    def getNext(self):
        return self.next

    def setData(self, newdata):
        self.data = newdata

    def getData(self):
        return self.data

class Node(object):
    def __init__(self, data):
        self.next = None
        self.data = data

    def setNext(self, newnext):
        self.next = newnext

    def getNext(self):
        return self.next

    def setData(self, newdata):
        self.data = newdata

    def getData(self):
        return self.data


class LinkedList(object):
    def __init__(self):
        self.size = 0
        self.head = Node(0)

    def append(self, data, num):
        newnode = Node(data)
        temp = self.head
        if num == 0:  # 头插法
            newnode.setNext(temp.getNext())
            temp.setNext(newnode)
            self.size += 1
            return True

        if num == 1:  # 尾插法
            while temp.getNext() != None:
                temp = temp.getNext()
            temp.setNext(newnode)
            self.size += 1
            return True

    def insert(self, i, data):
        if i < 0 and i < -1 or i > self.length():
            print("下标越界")
            return False
        temp = self.head
        newnode = Node(data)
        if i == -1:
            while temp.getNext() != None:
                temp = temp.getNext()
            temp.setNext(newnode)
            self.size += 1
            return True

        else:
            for a in range(1, self.length() + 1):
                if i == a and temp != None:
                    newnode.setNext(temp.getNext())
                    temp.setNext(newnode)
                    self.size += 1
                    return True
                temp = temp.getNext()

    def remove(self, data):
        if self.length() > 0:
            current = self.head.getNext()
            previous = self.head
            while current != None:
                if current.getData() == data:
                    previous.setNext(current.getNext())
                    current = None
                    self.size -= 1
                    return True
                previous = current
                current = current.getNext()
            return "不存在"
        else:
            return "空链表"

    def get(self, i):
        if i < 1 or i > self.length():
            print("下标越界")
        temp = self.head
        for a in range(1, self.length() + 1):
            if a == i and temp.getNext() != None:
                data = temp.getNext().getData()
                return data
            temp = temp.getNext()
        return False

    def update(self, i, data):
        if i < 1 or i > self.length():
            print("下标越界")
        temp = self.head
        for a in range(1, self.length() + 1):
            if a == i and temp != None:
                temp.getNext().setData(data)
                return True
            temp = temp.getNext()
        return False

    def delete(self, i):
        if i < 1 or i > self.length() + 1:
            print("下标越界")
        temp = self.head
        for a in range(1, self.length() + 1):
            if a == i and temp.getNext() != None:
                deleteNode = temp.getNext().getData()
                temp.setNext(temp.getNext().getNext())
                # temp.setNext(None)
                return deleteNode
            temp = temp.getNext()
        return -1

    def contains(self, data):
        temp = self.head.getNext()
        while temp != None:
            if temp.getData() == data:
                return True
            temp = temp.getNext()
        return False

    def search(self, data):
        if self.length()>0:
            temp = self.head.getNext()
            for i in range(1, self.length()):
                if temp.getData() == data and temp != None:
                    return i
                temp = temp.getNext()
            return "不存在"
        else:
            return "空链表"

    def clear(self):
        self.head.setNext(None)
        self.size = 0
        return True

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

    def length(self):
        count = 0
        temp = self.head
        while temp.getNext() != None:
            count += 1
            temp = temp.getNext()
        return count

    def display(self):
        if self.length() > 0:
            temp = self.head.getNext()
            while temp != None:
                if temp.getNext() != None:
                    print(temp.getData(), end=',')
                else:
                    print(temp.getData(), end='')
                temp = temp.getNext()
            print()
        else:
            print(None)


def main():
    link = LinkedList()
    link.append(12, 0)
    link.append("python", 0)
    link.append(3, 0)
    link.display()
    # link.clear()
    print(link.search(3))
    link.display()


if __name__ == "__main__":
    main()