Issue checking if binary tree is also binary search tree

Question

I\'m trying to solve this problem but I\'m having some troubles:

In a binary search tree (BST):

• The data value of every node in a

Answer 1

Something like the following should work

boolean check(Node root) {   

    if (root == null) {
        return true;
    }


    if (root.left != null && max(root.left) > root.data  ) {
        return false
    }

    if (root.right != null && max(root.right) < root.data ) {
        return false;
    }

    return check(root.left) && check(root.right);
}

Note:

• this is fairly inefficient
• you need to implement max()