PYTHON 3 PLEASE FOLLOW INSTRUCTIONS

COMPLETE CODE

Problem : Complete the function isValidBST() to take in a root node of a binary tree and return True if the tree is a valid BST, False otherwise.

CODE :

class Node: def __init__(self, value): self.value = value self.left = None self.right = None def isValidBST(root): # todo

root = Node(7) # left sub root.left = Node(4) root.left.left = Node(1) root.left.right = Node(5) # right sub root.right = Node(10) root.right.right = Node(13) """ 7 / \ 4 10 / \ \ 1 5 13 """

isValidBST(root) #must return True root.value = 3 isValidBST(root) #must return False