实现读入一串字符创建一棵二叉排序树，然后分别实现：二叉排序树的查找；二叉排序树的插入；二叉排序树的删除等操作

以下是实现读入一串字符创建一棵二叉排序树，然后分别实现二叉排序树的查找、插入、删除等操作的Python代码：

# 定义二叉排序树的节点类
class TreeNode:
    def __init__(self, val):
        self.val = val
        self.left = None
        self.right = None

# 定义二叉排序树类
class BST:
    def __init__(self):
        self.root = None

    # 插入节点
    def insert(self, val):
        if not self.root:
            self.root = TreeNode(val)
            return
        cur = self.root
        while cur:
            if val < cur.val:
                if not cur.left:
                    cur.left = TreeNode(val)
                    return
                cur = cur.left
            else:
                if not cur.right:
                    cur.right = TreeNode(val)
                    return
                cur = cur.right

    # 查找节点
    def search(self, val):
        cur = self.root
        while cur:
            if cur.val == val:
                return True
            elif cur.val > val:
                cur = cur.left
            else:
                cur = cur.right
        return False

    # 删除节点
    def delete(self, val):
        def find_min(root):
            while root.left:
                root = root.left
            return root

        def delete_node(root, val):
            if not root:
                return None
            if root.val == val:
                if not root.left and not root.right:
                    return None
                if not root.left:
                    return root.right
                if not root.right:
                    return root.left
                min_node = find_min(root.right)
                root.val = min_node.val
                root.right = delete_node(root.right, min_node.val)
            elif root.val > val:
                root.left = delete_node(root.left, val)
            else:
                root.right = delete_node(root.right, val)
            return root

        self.root = delete_node(self.root, val)

# 读入一串字符
s = input()

# 创建二叉排序树
bst = BST()
for c in s:
    bst.insert(c)

# 查找节点
print(bst.search('a'))

# 插入节点
bst.insert('b')

# 删除节点
bst.delete('a')