BinarySearchTree.java

class Node {
    Node left, right;
    int data;

    public Node(int data) {
        this.data = data;
    }

    public void insert(int value) {
        if(value <= data) {
            if(left == null)
                left = new Node(value);
            else
                left.insert(value);
        } else {
            if(right == null)
                right = new Node(value);
             else 
               right.insert(value);
        }
    }

    public boolean has(int value) {
        if(value == data) 
            return true;
        else if(value < data) {
            if(left == null)
                return false;
            else
                return left.has(value);
        } else {
            if(right == null)
                return false;
            else
                return right.has(value);
        }
    }

    public void printInOrder() {
        if(left != null) {
            left.printInOrder();
        }
        System.out.println(data);
        if(right != null) {
            right.printInOrder();
        }
    }

}