如何使用Python在二叉搜索树中实现搜索函数？

Question

函数searchNode工作不正常。当搜索二叉树中的元素时，它返回None而不是True。我不明白为什么它是None，因为它应该返回True或False，但决不会返回一个。你能告诉我怎么修理吗？在

class Node:
def __init__(self, value):
    self.value = value
    self.left = None
    self.right = None

class BinarySearchTree:
def __init__(self):
    self.root = None
    self.visited = 0

def insert(self,value):
    if self.root is None:
        self.root =  Node(value)
    else:
        self.insertNode(self.root, value)

def insertNode(self,current, value):
    if value <= current.value:
        if  current.left:
            self.insertNode(current.left, value)
        else:
            current.left = Node(value)
    else:
        if current.right:
            self.insertNode(current.right, value)
        else:
            current.right = Node(value)

def fromArray(self, newarr):
    for each in newarr:
        self.insert(each)
    return

def search(self, value):
    self.visited = 0
    self.searchNode(self.root, value)

def searchNode(self,current,value):
    if (current is None):
        return False
    elif (value == current.value):
        return True
    elif (value < current.value):
        self.visited += 1
        return self.searchNode(current.left, value)
    else:
        self.visited += 1
        return self.searchNode(current.right, value)

Answer 1

您不会在search中返回任何内容。您可能希望return self.searchNode(self.root, value)而不是直接调用它。在