// Helene Martin, CSE 143
// An IntTree object represents an entire binary tree of ints.

public class IntTree {
   private IntTreeNode overallRoot;

   // Constructs an empty binary tree.
   public IntTree() {
      overallRoot = null;
   }

   // Constructs a binary tree with the given node as its root.
   // Note: this is hacky and just useful for testing
   public IntTree(IntTreeNode root) {
      overallRoot = root;
   }

   // Prints a pre-order traversal of this tree.
   public void printPreorder() {
      printPreorder(overallRoot);
   }

   // Prints a pre-order traversal of the tree starting at the specified root
   private void printPreorder(IntTreeNode root) {
      // implicit base case: do nothing when we reach a null root
      if (root != null) {
         System.out.print(root.data + " ");
         printPreorder(root.left);
         printPreorder(root.right);
      }
   }

   // Prints an in-order traversal of this tree.
   public void printInorder() {
      printInorder(overallRoot);
   }

   // Prints an in-order traversal of the tree starting at the specified root
   private void printInorder(IntTreeNode root) {
      if (root != null) {
         printInorder(root.left);
         System.out.print(root.data + " ");
         printInorder(root.right);
      }
   }

   // Prints a post-order traversal of this tree.
   public void printPostorder() {
      printPostorder(overallRoot);
   }

   // Prints a post-order traversal of the tree starting at the specified root
   private void printPostorder(IntTreeNode root) {
      if (root != null) {
         printPostorder(root.left);
         printPostorder(root.right);
         System.out.print(root.data + " ");
      }
   }
}