/** Let's make a tree, and print it out.
 *  There are 2 constructors we can call -- we can create a tree with a
 *  single node, or with 2 existing trees and a new node , we can make a 
 *  bigger tree.
 */
import java.util.Iterator;

public class Driver
{
  public static void main(String [] args)
  {
    Tree c = new Tree(new Item("C"));
    Tree x = new Tree(new Item("X"));
    Tree h = new Tree(new Item("H"), c, x);
    Tree s = new Tree(new Item("S"));
    Tree r = new Tree(new Item("R"), s, h);
    Tree j = new Tree(new Item("J"));
    //Tree q = new Tree(new Item("Q"), j, null);
    Tree q = new Tree(new Item("Q"));
    Tree t = new Tree(new Item("T"), r, q);

    // default printout (preorder shown vertically)
    System.out.println(t);

    // 3 traversals
    // When we traverse, we need to remember to call getData because
    // the node itself does not have toString.  We're only interested in
    // seeing the data (string) within.
    Iterator preorder = t.preorderIterator();

    System.out.print("Preorder:   ");
    while (preorder.hasNext())
      System.out.print(((Node) preorder.next()).getData() + " ");
    System.out.println();

    // When your traversals are ready,
    // un-comment-out this code.
    /*
    Iterator inorder = t.inorderIterator();
    Iterator postorder = t.postorderIterator();

    System.out.print("\nInorder:    ");
    while (inorder.hasNext())
      System.out.print(((Node) inorder.next()).getData() + " ");
    System.out.print("\nPostorder:  ");
    while (postorder.hasNext())
      System.out.print(((Node) postorder.next()).getData() + " ");
    System.out.println();
    */

    // Let's create a second tree, this time also to show fully
    // parenthesized version.
    Tree t1 = new Tree(new Item("25"));
    Tree t2 = new Tree(new Item("5"));
    Tree t3 = new Tree(new Item("6"));
    Tree t4 = new Tree(new Item("7"));
    Tree t5 = new Tree(new Item("9"));
    Tree diff = new Tree(new Item("-"), t1, t2);
    Tree sum = new Tree(new Item("+"), t3, t4);
    Tree prod = new Tree(new Item("*"), diff, sum);
    Tree total = new Tree(new Item("+"), prod, t5);

    // When you are ready to test, un-comment-out this code.
    /*
    System.out.println("\nA postfix expression:");
    postorder = total.postorderIterator();
    while(postorder.hasNext())
      System.out.print(((Node) postorder.next()).getData() + " ");
    System.out.println();

    System.out.println("Fully parenthesized infix:");
    
    // ADD CODE HERE that will create iterator object, and then traverse
    // this object.
    
    System.out.println();
    */
  }
}