BinaryTree

import java.util.*;

public class Tree {

    Node root;

    public void add(int value) {
        root = addRecursive(root, value);
    }

    private Node addRecursive(Node current, int value) {
        if (current == null) {
            return new Node(value);
        }
        if (value < current.value) {
            current.left = addRecursive(current.left, value);
        } else if (value > current.value) {
            current.right = addRecursive(current.right, value);
        }

        return current;
    }

    public boolean isEmpty() {
        return root == null;
    }

    public void dfs(Node node) {
        if (node != null) {
            System.out.print(" " + node.value);
            dfs(node.left);
            dfs(node.right);
        }
    }

    public void bfs() {
        if (root == null) {
            return;
        }

        Queue<Node> nodes = new LinkedList<>();
        nodes.add(root);

        while (!nodes.isEmpty()) {

            Node node = nodes.remove();

            System.out.print(" " + node.value);

            if (node.left != null) {
                nodes.add(node.left);
            }

            if (node.right!= null) {
                nodes.add(node.right);
            }
        }
    }

}

class Node {

    int value;
    Node left;
    Node right;

    Node(int value) {
        this.value = value;
        right = null;
        left = null;
    }
}