Visit HackerRank's Data Structures website, visit the subdomains and commit new problem solutions at the repo's Data Structures folder.

Rules:

1. Solutions must be correct (obviously), I will review them before merging.
2. The solution's directory path must be according to the subdomain HackerRank provides for Data Structures. Example: /Data Structures/Subdomain name/Solution.java or /Data Structures/Subdomain name/RelevantFileName.java
3. Code can be done in any preferred language but Java and JavaScript are recommended. Someone who provides the solution in Kotlin/PHP (or any other language except recommended ones) will be considered later.
4. Code should be formatted properly. Unformatted code will be disregarded.
5. The solution you submit should be of your own.

Currently, there is no problem description file for 10 Days of Statistics.

Add a README.md file for each day problem explaining how to solve the issue, and if possible what the solution code means.

Example: For Day 0: Mean, Median and Mode, add the README file that explains above so that we have two files in the Day 0 folder; one of the actual solution and second the README file.

Your device hardware:

Issue details:
Given the root node of a binary tree, can you determine if it's also a binary search tree?
Complete the function which has parameter: a pointer to the root of a binary tree. It must return a boolean denoting whether or not the binary tree is a binary search tree. You may have to write one or more helper functions to complete this challenge.

boolean checkBST(Node root) {
return checkBSTUtil(root, null, null);
}
private boolean checkBSTUtil(Node root, Node min, Node max){
if(root == null){
return true;
}
if(min != null && min.data >= root.data){
return false;
}
if(max != null && root.data >= max.data){
return false;
}
return checkBSTUtil(root.left, min, root) && checkBSTUtil(root.right, root, max);
}

Log (optional):

Currently, the repo only contains solution's problems but are not descriptive. You can add a README.md file describing the problem or solution (if possible) in detail.

You can add more solutions to any new problems. Make sure the solution(s) is/are in Java language.