Check Valid BST Function | Dataford Interview Questions

Write a function to determine if a given binary tree is a valid Binary Search Tree.

Use the function signature is_valid_bst(root). Represent each node as an object with val, left, and right fields, where a missing child is null. Return true only when every node in the left subtree is strictly smaller and every node in the right subtree is strictly larger than the node's value. Duplicate values are invalid.

Constraints

0 <= number of nodes <= 1000
-10^9 <= node.val <= 10^9
Each node has exactly one integer val field and left and right child fields
Duplicate values are not allowed in a valid tree

Function Signature

def is_valid_bst(root):

Your question is Check Valid BST Function. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Write a function to determine if a given binary tree is a valid Binary Search Tree.

Constraints

0 <= number of nodes <= 1000
-10^9 <= node.val <= 10^9
Each node has exactly one integer val field and left and right child fields
Duplicate values are not allowed in a valid tree

Function Signature

def is_valid_bst(root):

Your question is Check Valid BST Function. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.