# Validate a Binary Search Tree using Python

Validating a binary search tree is a great question for coding interviews. It means writing an algorithm to check whether a binary tree is a binary search tree or not. In this article, I’ll walk you through how to write an algorithm to validate a binary search tree using Python.

## How To Validate a Binary Search tree?

A binary search tree (BST) is a binary tree whose elements are positioned in a special order such that in each binary search tree all values in the left subtree are less than those in the subtree on the right.

A binary tree is a tree in which each node has two child nodes. The first child node is known as the left child node and the second child node is known as the right child node. Whereas a binary search tree is a binary tree where each node has a unique key such that each left node is less than each right node.

## Validating a Binary Search Tree: Problem Statement

In the coding interviews the problem statement that you get for validating a binary tree is like this:

“You are given the root of a binary tree, you need to write an algorithm to determine if it is a valid binary search tree or not.”

## Validate a Binary Search Tree using Python

So as per the understanding of what a binary search tree is and what the problem statement reads, here is how to validate a binary search tree using Python:

### Summary

So this is how you need to write an algorithm to validate a binary search tree using the Python programming language. It is an important concept that you should know for coding interviews. While validating a binary search tree always remember that each left node is smaller than each right node.

Also, Read – All Machine Learning Algorithms Explained using Python.

I hope you liked this article on how to write an algorithm for validating a binary search tree using the Python programming language. Feel free to ask your valuable questions in the comments section below.

##### Aman Kharwal

I'm a writer and data scientist on a mission to educate others about the incredible power of dataðŸ“ˆ.

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