Tree

package main;

public class Tree {

    class Node
    {
        int key;
        Node left;
        Node right;

        public Node(int item)
        {
            key = item;
            right = null;
            left = null;
        }
    }

    Node root;

    Tree()
    {
        root = null;
    }

    void insert(int key)
    {
        root = insertRec(key, root);
    }

    Node insertRec(int key, Node root)
    {
        if (root == null)
        {
            root = new Node(key);

            return root;
        }

        if (key < root.key)
        {
            root.left = insertRec(key, root.left);
        }

        else
        {
            root.right = insertRec(key, root.right);
        }

        return root;
    }

    void inorder()
    {
        inorderRec(root);
    }

    void inorderRec(Node root)
    {
        if (root != null)
        {
            inorderRec(root.left);

            System.out.print(" " + root.key + " ");

            inorderRec(root.right);
        }

    }
}