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二分探索木のノードを削除python

以下のコードは私の二分探索木の実装であり、ノードを削除するためにdeleteメソッドを実装したいと思います。以下は私の実装ですが、実行すると

bst = BSTRee()
bst.insert(5)
bst.insert(11)
bst.insert(3)
bst.insert(4)
bst.insert(12)
bst.insert(2)
bst.delete(3)

deleteメソッドを呼び出しても、何もしませんでした。誰かが私がそれを修正するのを手伝ってもらえますか？以下のリンクは、github上の私のコードです。手伝ってくれてどうもありがとう。 https://github.com/hly189/sort/blob/master/tree/BST.py

class BSTreeNode
    def ____init__(self, value): 
        self.value = value 
        self.left = None 
        self.right = None

   def insert(self,key): 
        if self.value == key: 
            print ("the node already exists")
            return False 
        Elif self.value > key: 
            if self.left is not None: 
               return self.left.insert(key)
            else: 
               self.left = BSTreeNode(key)
               return True
        else: 
             if self.right is not None: 
               return self.right.insert(key)
            else: 
               self.right = BSTreeNode(key)
               return False

    def delete(self, node, k):
            if node == None: 
               return None
            Elif node.value == k: 
               if node.left is None and node.right is None: 
               return None
            Elif node.left is None: 
                return node.right
            Elif node.right is None: 
                return node.left 
            else: 
                node.value = get_min(node.right)
                node.right.delete(node.right,node.value)
            Elif k < node.value: 
                node.left.delete(node.left,k)
            else: 
                node.right.delete(node.right,k)
            return node

class BSTree: 
    def __init__(self): 
           self.root = None 

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

    def insert(self,data): 
           if self.root: 
               self.root.insert(data)
           else: 
               self.root = BSTreeNode(data)
               return True 
    def find_min(self,node):
           current_node = node
           while current_node.left: 
               current_node = current_node.left
           return current_node


def get_min(node): 
    current_node = node
    while current_node.left: 
        current_node = current_node.left
    return str(current_node.value)

def print_helper(root, indent):
    if root is not None:
        print_helper(root.right, indent + "   ")
        print (indent + str(root.value))
        print_helper(root.left, indent + "   ")

def print_tree(root):
     print_helper(root, "")
pythondata-structuresbinary-search-tree
5
Alexander
def delete(self, key):
    """ delete the node with the given key and return the 
    root node of the tree """

    if self.key == key:
        # found the node we need to delete

        if self.right and self.left: 

            # get the successor node and its parent 
            [psucc, succ] = self.right._findMin(self)

            # splice out the successor
            # (we need the parent to do this) 

            if psucc.left == succ:
                psucc.left = succ.right
            else:
                psucc.right = succ.right

            # reset the left and right children of the successor

            succ.left = self.left
            succ.right = self.right

            return succ                

        else:
            # "easier" case
            if self.left:
                return self.left    # promote the left subtree
            else:
                return self.right   # promote the right subtree 
    else:
        if self.key > key:          # key should be in the left subtree
            if self.left:
                self.left = self.left.delete(key)
            # else the key is not in the tree 

        else:                       # key should be in the right subtree
            if self.right:
                self.right = self.right.delete(key)

    return self

def _findMin(self, parent):
    """ return the minimum node in the current tree and its parent """

    # we use an ugly trick: the parent node is passed in as an argument
    # so that eventually when the leftmost child is reached, the 
    # call can return both the parent to the successor and the successor

    if self.left:
        return self.left._findMin(self)
    else:
        return [parent, self]

これは役立つかもしれません。完全なコードとより良い理解については、コードPythonのバイナリ検索ツリー にアクセスしてください。

説明のためにPythonのBSTに関する注記 私の知識によれば、正常に動作しています。

6
Prashant Shukla