import ch08.trees.BinarySearchTree;
import support.BSTNode;
public class Balance {
    private static final int INORDER = 1;
    private static BinarySearchTree<Long> tree;
    private static Long[] array;

    public static void main(String[] args) {
	// Create a fully UNbalanced tree and print its height
	tree = new BinarySearchTree<Long>();
	for (int i=0; i<15; i++)
	    tree.add(new Long(i));
	System.out.println("The unbalanced height is " + height(tree.getRoot()));

	// Balance the tree and print its height
	balance();
	System.out.println("The balanced height is " + height(tree.getRoot()));
    }

    private static int height(BSTNode<Long> tree) {
	if (tree == null)
	    throw new RuntimeException("Height of empty tree undefined");
	return recHeight(tree);
    }

    private static int recHeight(BSTNode<Long> tree) {
	if (tree.getLeft()==null && tree.getRight()==null)
	    return 0;
	int max = 0;
	if (tree.getLeft()!=null) {
	    int leftHeight = recHeight(tree.getLeft());
	    if (leftHeight > max)
		max = leftHeight;
	}
	if (tree.getRight()!=null) {
	    int rightHeight = recHeight(tree.getRight());
	    if (rightHeight > max)
		max = rightHeight;
	}
	return 1 + max;
    }

    private static void balance() {
	int n = tree.reset(INORDER);
	array = new Long[n];
	for (int i=0; i<n; i++)
	    array[i] = tree.getNext();
	tree = new BinarySearchTree<Long>();
	insertTree(0, n-1);
    }

    private static void insertTree(int lo, int hi) {
	if (lo <= hi) {
	    int mid = (lo+hi)/2;
	    tree.add(array[mid]);
	    insertTree(lo, mid-1);
	    insertTree(mid+1, hi);
	}
    }
}
// Local Variables:
// compile-command: "export CLASSPATH=/a/dale-dataStructures/ajgFiles/:.; \
// (javac Balance.java && java Balance)"
// End: