My solution to HackerRank Challenge “Trees: Is This a Binary Search Tree?”

This is my solution to challenge “Trees: Is This a Binary Search Tree?” on HackerRank. Click here to see the challenge.

import java.io.*;
/* Hidden stub code will pass a root argument to the function below. Complete the function to solve the challenge. Hint: you may want to write one or more helper functions.  

The Node class is defined as follows:
    class Node {
        int data;
        Node left;
        Node right;
     }
*/
    boolean checkBST(Node root) {
        return checkBSTRecursive(root,Integer.MIN_VALUE, Integer.MAX_VALUE);
    }
    boolean checkBSTRecursive(Node root, int min, int max) {
        if(root == null){
            return true;
        }
        if(root.data < min || root.data > max){
            return false;
        }
        if(root.left != null && root.right != null){
            if(root.left.data > root.data || root.right.data < root.data){
                return false;
            }
        }
        return checkBSTRecursive(root.left,min, root.data-1) && checkBSTRecursive(root.right,root.data+1,max);
    }