Problem: Validate Binary Search Tree

Medium

30 min

Explore the method to determine if a binary tree is a valid binary search tree. Understand how to verify that each node satisfies the BST properties by using depth-first search, ensuring all left subtree nodes are less and right subtree nodes are greater. This lesson helps you implement and test your solution effectively.

Statement

Given the root of a binary tree, check whether it is a valid binary search tree (BST).

A binary tree is a valid BST if for every node:

The left subtree of a node contains only nodes with keys less than the node’s key.
The right subtree of a node contains only nodes with keys greater than the node’s key.
Both the left and right subtrees are valid BSTs.

Constraints:

$-10^{4} \leq$ Node.data $\leq 10^{4}$
The tree contains nodes in the range $[1, 500]$ .

Problem: Validate Binary Search Tree

Medium

30 min

Statement

Given the root of a binary tree, check whether it is a valid binary search tree (BST).

A binary tree is a valid BST if for every node:

The left subtree of a node contains only nodes with keys less than the node’s key.
The right subtree of a node contains only nodes with keys greater than the node’s key.
Both the left and right subtrees are valid BSTs.

Constraints:

$-10^{4} \leq$ Node.data $\leq 10^{4}$
The tree contains nodes in the range $[1, 500]$ .

Problem: Validate Binary Search Tree

Statement

Examples

Understand the problem

Figure it out!

Try it yourself

Problem: Validate Binary Search Tree

Statement

Examples

Understand the problem

Figure it out!

Try it yourself