Solution.java

/*  
 *      DeveloperName(): Jignesh Chudasama
 *      GithubName(): https://github.com/Jignesh-81726
 */

/* 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 check(root,Integer.MIN_VALUE,Integer.MAX_VALUE);
}
boolean check(Node n, int min, int max){
	if(n==null)
		return true;
	if(n.data <= min || n.data >= max)
		return false;
	return check(n.left, min, n.data) 
		&& check(n.right, n.data, max);
}