Binary Tree Validation

You are given the root of a binary tree. You need to determine if it is a valid binary search tree (BST).

A valid BST is defined as follows:

• The left subtree of a node contains only nodes with values less than or equal to the node’s value.
• The right subtree of a node contains only nodes with values greater than or equal to the node’s value.
• Both the left and right subtrees must also be binary search trees.

Given the function def is_valid_bst(root: Node) -> bool:, return True if the binary tree is a valid BST. Otherwise, return False.

Example:

Input:

Converted Binary Tree.png

Output:

def is_valid_bst(Node(3)) -> True