class TreeNode:
	'''二叉搜索树节点的定义'''
	def __init__(self, val):
		self.val = val
		self.left = None
		self.right = None

class OperationTree:
	'''二叉搜索树操作'''
	def insert(self, root, val):
		'''二叉搜索树插入操作'''
		if root == None:
			root = TreeNode(val)
		elif val < root.val:
			root.left = self.insert(root.left, val)
		elif val > root.val:
			root.right = self.insert(root.right, val)
		return root

	def query(self, root, val):
		'''二叉搜索树查询操作'''
		if root == None:
			return False
		if root.val == val:
			return True
		elif val < root.val:
			return self.query(root.left, val)
		elif val > root.val:
			return self.query(root.right, val)

	def findMin(self, root):
		'''查找二叉搜索树中最小值点'''
		if root.left:
			return self.findMin(root.left)
		else:
			return root

	def findMax(self, root):
		'''查找二叉搜索树中最大值点'''
		if root.right:
			return self.findMax(root.right)
		else:
			return root

	def delNode(self, root, val):
		'''删除二叉搜索树中值为val的点'''
		if root == None:
			return 
		if val < root.val:
			root.left = self.delNode(root.left, val)
		elif val > root.val:
			root.right = self.delNode(root.right, val)
		# 当val == root.val时，分为三种情况：只有左子树或者只有右子树、有左右子树、即无左子树又无右子树
		else:
			if root.left and root.right:
				# 既有左子树又有右子树，则需找到右子树中最小值节点
				temp = self.findMin(root.right)
				root.val = temp.val
				# 再把右子树中最小值节点删除
				root.right = self.delNode(root.right, temp.val)
			elif root.right == None and root.left == None:
				# 左右子树都为空
				root = None
			elif root.right == None:
				# 只有左子树
				root = root.left
			elif root.left == None:
				# 只有右子树
				root = root.right
		return root

	def printTree(self, root):
		# 打印二叉搜索树(中序打印，有序数列)
		if root == None:
			return 
		self.printTree(root.left)
		print(root.val, end = ' ')
		self.printTree(root.right)

if __name__ == '__main__':
	List = [17,5,35,2,11,29,38,9,16,8]
	root = None
	op = OperationTree()
	for val in List:
		root = op.insert(root,val)
	print('中序打印二叉搜索树：', end = ' ')
	op.printTree(root)
	print('')
	print('根节点的值为：', root.val)
	print('树中最大值为:', op.findMax(root).val)
	print('树中最小值为:', op.findMin(root).val)
	print('查询树中值为5的节点:', op.query(root, 5))
	print('查询树中值为100的节点:', op.query(root, 100))
	print('删除树中值为16的节点:', end = ' ')
	root = op.delNode(root, 16)
	op.printTree(root)
	print('')
	print('删除树中值为5的节点:', end = ' ')
	root = op.delNode(root, 5)
	op.printTree(root)
	print('')