无法删除二叉搜索树中的根节点

问题描述

**删除根(我输入强文本的第一个节点)节点显示错误“TreeNode”对象没有属性“findSuccessor” 当我尝试删除插入的第一个节点时,它显示一个属性 eroor 但稍后插入的节点会被删除 你能告诉我代码有什么问题吗**

class TreeNode:
    
    def __init__(self,key,val,left=None,right=None,parent=None):
        self.key = key
        self.payload = val
        self.leftChild = left
        self.rightChild = right
        self.parent = parent

    def hasLeftChild(self):
        return self.leftChild

    def hasRightChild(self):
        return self.rightChild

    def isLeftChild(self):
        return self.parent and self.parent.leftChild == self

    def isRightChild(self):
        return self.parent and self.parent.rightChild == self

    def isRoot(self):
        return not self.parent

    def isLeaf(self):
        return not (self.rightChild or self.leftChild)

    def hasAnyChildren(self):
        return self.rightChild or self.leftChild

    def hasBothChildren(self):
        return self.rightChild and self.leftChild

    def replaceNodeData(self,value,lc,rc):
        self.key = key
        self.payload = value
        self.leftChild = lc
        self.rightChild = rc
        if self.hasLeftChild():
            self.leftChild.parent = self
        if self.hasRightChild():
            self.rightChild.parent = self


class BinarySearchTree:

    def __init__(self):
        self.root = None
        self.size = 0

    def length(self):
        return self.size

    def __len__(self):
        return self.size

    def put(self,val):
        if self.root:
            self._put(key,self.root)
        else:
            self.root = TreeNode(key,val)
        self.size = self.size + 1

    def _put(self,currentNode):
        if key < currentNode.key:
            if currentNode.hasLeftChild():
                   self._put(key,currentNode.leftChild)
            else:
                   currentNode.leftChild = TreeNode(key,parent=currentNode)
        else:
            if currentNode.hasRightChild():
                   self._put(key,currentNode.rightChild)
            else:
                   currentNode.rightChild = TreeNode(key,parent=currentNode)

    def __setitem__(self,k,v):
        self.put(k,v)

    def get(self,key):
        if self.root:
            res = self._get(key,self.root)
            if res:
                
                return res.payload
            else:
                return None
        else:
            return None

    def _get(self,currentNode):
        
        if not currentNode:
            return None
        elif currentNode.key == key:
            return currentNode
        elif key < currentNode.key:
            return self._get(key,currentNode.leftChild)
        else:
            return self._get(key,currentNode.rightChild)

    def __getitem__(self,key):
        return self.get(key)

    def __contains__(self,key):
        if self._get(key,self.root):
            return True
        else:
            return False

    def delete(self,key):
        
        if self.size > 1:
            
            nodetoRemove = self._get(key,self.root)
            if nodetoRemove:
                self.remove(nodetoRemove)
                self.size = self.size-1
            else:
                raise KeyError('Error,key not in tree')
        elif self.size == 1 and self.root.key == key:
            self.root = None
            self.size = self.size - 1
        else:
            raise KeyError('Error,key not in tree')

    def __delitem__(self,key):
        
        self.delete(key)

    def spliceOut(self):
        if self.isLeaf():
            if self.isLeftChild():
                
                self.parent.leftChild = None
            else:
                self.parent.rightChild = None
        elif self.hasAnyChildren():
            if self.hasLeftChild():
                
                if self.isLeftChild():
                    
                    self.parent.leftChild = self.leftChild
                else:
                    
                    self.parent.rightChild = self.leftChild
                    self.leftChild.parent = self.parent
        else:
                    
            if self.isLeftChild():
                        
                self.parent.leftChild = self.rightChild
            else:
                self.parent.rightChild = self.rightChild
                self.rightChild.parent = self.parent

    def findSuccessor(self):
        
        succ = None
        if self.hasRightChild():
            succ = self.rightChild.findMin()
        else:
            if self.parent:
                
                if self.isLeftChild():
                    
                    succ = self.parent
                else:
                    self.parent.rightChild = None
                    succ = self.parent.findSuccessor()
                    self.parent.rightChild = self
        return succ

    def findMin(self):
        
        current = self
        while current.hasLeftChild():
            current = current.leftChild
        return current

    def remove(self,currentNode):
        
        if currentNode.isLeaf(): #leaf
            if currentNode == currentNode.parent.leftChild:
                currentNode.parent.leftChild = None
            else:
                currentNode.parent.rightChild = None
        elif currentNode.hasBothChildren(): #interior
            
            succ = currentNode.findSuccessor()
            succ.spliceOut()
            currentNode.key = succ.key
            currentNode.payload = succ.payload

        else: # this node has one child
            if currentNode.hasLeftChild():
                if currentNode.isLeftChild():
                    currentNode.leftChild.parent = currentNode.parent
                    currentNode.parent.leftChild = currentNode.leftChild
                elif currentNode.isRightChild():
                    currentNode.leftChild.parent = currentNode.parent
                    currentNode.parent.rightChild = currentNode.leftChild
                else:
                
                    currentNode.replaceNodeData(currentNode.leftChild.key,currentNode.leftChild.payload,currentNode.leftChild.leftChild,currentNode.leftChild.rightChild)
            else:
                
                if currentNode.isLeftChild():
                    currentNode.rightChild.parent = currentNode.parent
                    currentNode.parent.leftChild = currentNode.rightChild
                elif currentNode.isRightChild():
                    currentNode.rightChild.parent = currentNode.parent
                    currentNode.parent.rightChild = currentNode.rightChild
                else:
                    currentNode.replaceNodeData(currentNode.rightChild.key,currentNode.rightChild.payload,currentNode.rightChild.leftChild,currentNode.rightChild.rightChild)

解决方法

暂无找到可以解决该程序问题的有效方法,小编努力寻找整理中!

如果你已经找到好的解决方法,欢迎将解决方案带上本链接一起发送给小编。

小编邮箱:dio#foxmail.com (将#修改为@)