Question

我想在二进制搜索树中插入一个“新”节点。但是在运行代码时，我遇到了诸如以下错误：

an infinte loop (with nothing as display) 
 temp.data(nonetype) has no value.

您能看到这段代码中的错误是什么以及如何纠正该错误。

请参阅我的以下代码：

class Node:
    def __init__(self,data=0):
        self.data = data
        self.left = None
        self.right = None
class tree:
    def __init__(self):
        self.root = None
    def insert(self,data):
        temp = root
        new_node = Node(data)
        new_node.left = None
        new_node.right =None
        while temp.left and temp.right:
            if new_node.data < temp.data:
                temp  = temp.left
            else:
                temp = temp.right
        if temp.data > new_node.data:
            temp.left = new_node
        else:
            temp.right = new_node
    def display(self,temp):
        if temp == None:
            return
        else:
            print(temp.data,end = " ")
            self.display(temp.left)
            self.display(temp.right)        
if __name__=='__main__':
    mylist = tree()
    root = Node(19)
    root.left =Node(12)
    root.right = Node(30)
    mylist.insert(10)
    mylist.display()

Answer 1

当节点只有左或右子树时，将不考虑您的代码。在遍历节点时，您需要检查您的左孩子或右孩子是否为None类型。
我修改了树类以初始化构造函数中的root。修改后的代码：

class Node:
    def __init__(self,data=0):
        self.data = data
        self.left = None
        self.right = None
class tree:
    def __init__(self,root):
        self.root = root
    def insert(self,data):
        temp = self.root
        new_node = Node(data)
        new_node.left = None #remove this as it will be set to none in Node constructor itself. 
        new_node.right =None #remove this
        while temp.left or temp.right:
            if new_node.data < temp.data:
                if temp.left != None:
                    temp  = temp.left
                else:
                    break
            else:
                if temp.right !=None:
                    temp = temp.right
                else:
                    break

        if temp.data > new_node.data: 
            temp.left = new_node                   
        else:
            temp.right = new_node
    def display(self,temp):
        if temp == None:
            return
        else:
            print(temp.data,end = " ")
            self.display(temp.left)
            self.display(temp.right)        
if __name__=='__main__':    
    root = Node(19)
    #root.left =Node(12) #insert using insert function of tree class
    #root.right = Node(30) 
    mylist = tree(root)
    mylist.insert(12)
    mylist.insert(30)
    mylist.insert(10)
    mylist.insert(20)
    mylist.insert(18)
    mylist.insert(9)
    mylist.display(root)

在BST中插入节点时不显示任何输出

1 个答案: