title: I have writen a binary search but got some error
body: <p>I written an binary tree with post order, but I got some error message..</p>
  <p><img src="https://i.stack.imgur.com/bPcPc.png" alt="error picture" /></p>
  <pre><code> public static void main(String [] args) {
      int input;
      Scanner sc = new Scanner(System.in);
      System.out.print(&quot;Enter the number of the data: &quot;);
      input = sc.nextInt();
      int[] data;
  
      data = new int[input];
      BSTree tree = new BSTree();
      System.out.println(&quot;Enter the values: &quot;);
          for (int i = 0; i &lt; input; i++) {
              data[i] = sc.nextInt();
          }
              System.out.print(data + &quot; &quot;);
              tree.insert(data[input]);
          System.out.println();
  
          System.out.println(&quot;It used preorder.&quot;);
          System.out.println(&quot;BinarySearchTree - size: &quot; + tree.size() + &quot; height: &quot; + tree.height());
          tree.postorder();   // left right root
  </code></pre>
  <p>I can store 5 number now.  But now I can't show the my inserted data and the post order, whats going on?</p>
  <pre><code>    public static void main(String [] args) {
  int input;
  Scanner sc = new Scanner(System.in);
  System.out.print(&quot;Enter the number of the data: &quot;);
  input = sc.nextInt();
  
  int[] data = new int[input];
  BSTree tree = new BSTree();
  System.out.println(&quot;Enter the values: &quot;);
      for (int i = 0; i &lt; data.length; i++) {
          data[i] = sc.nextInt();
      }
          System.out.print(data + &quot; &quot;);
          tree.insert(input);
  
      System.out.println(&quot;It used preorder.&quot;);
      System.out.println(&quot;BinarySearchTree - size: &quot; + tree.size() + &quot; height: &quot; + tree.height());
      tree.postorder();
  </code></pre>
  <p>I prefer will show
  Inserted : 33 44 22 11 23
  postorder :</p>
  <p>and now show</p>
  <pre><code>   Enter the number of the data: 5
  Enter the values:
  32
  23
  13
  12
  4
  [I@5b6f7412 It used preorder.
  BinarySearchTree - size: 1 height: 0
  5
  </code></pre>