// Stuart Reges, 2/22/06
// modified by Marty Stepp 2/23/09
//
// A basic binary tree class that includes methods to construct a random tree
// of ints and to print its data using pre-, in-, or post-order traversals.

public class IntTree {
    private IntTreeNode overallRoot;

    // Constructs an empty binary tree (null root).
    public IntTree() {
        this(null);
    }
    
    // Constructs a binary tree with the given node as its root.
    public IntTree(IntTreeNode root) {
        overallRoot = root;
    }

    // Constructs a perfect binary tree of the given height with random
    // data values between 0 and 99 inclusive.
    // Throws an IllegalArgumentException if the height is less than 0.
    public IntTree(int height) {
        if (height < 0) {
            throw new IllegalArgumentException();
        }
        overallRoot = randomTree(height);
    }

    // Constructs and returns a reference to a full binary tree of height h
    // with random data values between 0 and 99 inclusive.
    // Precondition: height >= 0
    private IntTreeNode randomTree(int h) {
        if (h == 0) {
            return null;
        } else {
            int n = (int) (Math.random() * 100);
            IntTreeNode node = new IntTreeNode(n);
            node.left = randomTree(h - 1);
            node.right = randomTree(h - 1);
            return node;
        }
    }
    
    // Prints an in-order traversal of this tree's elements, separated by spaces.
    // A blank line of output is produced when the tree is empty.
    public void print() {
        print(overallRoot);
        System.out.println();   // end the line of output
    }
    
    // Prints an in-order traversal of the given root node's elements, 
    // separated by spaces.  No output is produced for an empty tree.
    private void print(IntTreeNode root) {
        if (root != null) {
            print(root.left);
            System.out.print(root.data + " ");
            print(root.right);
        }
    }

    
    // Prints a pre-order traversal of this tree's elements, separated by spaces.
    // A blank line of output is produced when the tree is empty.
    public void printPreOrder() {
        printPreOrder(overallRoot);
        System.out.println();   // end the line of output
    }
    
    // Prints a pre-order traversal of the given root node's elements, 
    // separated by spaces.  No output is produced for an empty tree.
    private void printPreOrder(IntTreeNode root) {
        if (root != null) {
            System.out.print(root.data + " ");
            printPreOrder(root.left);
            printPreOrder(root.right);
        }
    }
    
    // Prints a pre-order traversal of this tree's elements, separated by spaces.
    // A blank line of output is produced when the tree is empty.
    public void printPostOrder() {
        printPostOrder(overallRoot);
        System.out.println();   // end the line of output
    }
    
    // Prints a post-order traversal of the given root node's elements, 
    // separated by spaces.  No output is produced for an empty tree.
    private void printPostOrder(IntTreeNode root) {
        if (root != null) {
            printPostOrder(root.left);
            printPostOrder(root.right);
            System.out.print(root.data + " ");
        }
    }
}