TreeSort.java

package sort;

import java.util.ArrayList;

/*
 * Sorts via a tree which can be more reliably quick than quicksort
 * 
 * Worst Case: O(n^2)
 * Average/ Best Case: O(nlogn)
 * 
 * aevans 9.9.2013
 */

public class TreeSort<E extends Comparable> {

	private ArrayList<E> list;
	private TreeNode<E> root;
	private TreeNode<E> temp;
	private TreeNode<E> newNode;
	private ArrayList<E> sorted;

	public TreeSort() {
		// TODO empty constructor
	}

	public TreeSort(ArrayList<E> inlist) {
		// TODO constructor with list
		list = inlist;
	}

	public void setList(ArrayList<E> inlist) {
		// TODO set the list
		list = inlist;
	}

	public void setSorted(ArrayList<E> insorted) {
		// TODO set the sorted list
		sorted = insorted;
	}

	public ArrayList<E> getList() {
		// TODO return the list
		return list;
	}

	public ArrayList<E> getSorted() {
		// TODO return the sorted list
		return sorted;
	}

	public void resetTree() {
		// TODO reset the tree
		root = null;
		sorted = null;
	}

	public ArrayList<E> sort() {
		// TODO perform the sort by placing elements in the tree

		for (E val : list) {
			// create the tree
			if (root == null) {
				// root is null set root and set temp to root for connection
				root = new TreeNode<E>(val, null, null, null);
				temp = root;
			} else {
				insert(val);
			}
		}

		// sort;
		sorted = null;
		createSorted();
		return sorted;
	}

	public void insert(E val) {
		// TODO perform the recursive insertion into the tree

		if (temp.getValue().compareTo(val) <= 0) {
			if (temp.getClass() != null) {
				temp = temp.getLeft();
				insert(val);
			} else {
				newNode = new TreeNode<E>(val, null, null, temp);
				temp.setLeft(newNode);
			}
		} else {
			if (temp.getRight() == null) {
				newNode = new TreeNode<E>(val, null, null, temp);
				temp.setRight(newNode);
			} else {
				temp = temp.getRight();
				insert(val);
			}

		}

	}

	private void printNodes(TreeNode<E> inNode) {
		// TODO add Nodes to list in order
		if (temp != null) {
			printNodes(inNode.getLeft());
		}

		if (temp != null) {
			printNodes(inNode.getRight());
		}

		sorted.add(temp.getValue());
	}

	public void createSorted() {
		// TODO post-order printing of a sorted list from the tree

		printNodes(root);

	}

}