Cut the sticks! (HackerRank)

Stick.java

package com.jamesdaily.study;

public class Stick implements Comparable<Stick> {
	protected Integer length;

	public Stick(Integer length) {
		if (length == 0)
			throw new IllegalArgumentException("Stick cannot be length 0!");
		if (length < 0)
			throw new IllegalArgumentException(
					"Stick cannot be negative length!");
		setLength(length);
	}

	public Integer getLength() {
		return length;
	}

	protected void setLength(Integer length) {
		this.length = length;
	}

	public Integer reduceLengthBy(Integer cutLength) {
		if (this.getLength() < cutLength)
			throw new IllegalArgumentException("Cannot cut to negative length!");
		this.setLength(Math.max(0, this.length - cutLength));
		return this.getLength();
	}

	public Integer reduceLengthBy(Stick shorterStick) {
		return this.reduceLengthBy(shorterStick.getLength());
	}

	@Override
	public int compareTo(Stick otherStick) {
		return this.getLength() > otherStick.getLength() ? 1
				: this.getLength() < otherStick.getLength() ? -1 : 0;
	}

	@Override
	public String toString() {
		return this.length.toString();
	}

}

StickCutter.java

package com.jamesdaily.study;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.NoSuchElementException;

public class StickCutter {
	protected List<Stick> sticks;

	public StickCutter(Integer[] stickLengths) {
		this.sticks = new ArrayList<Stick>();
		for (Integer len : stickLengths) {
			this.sticks.add(new Stick(len));
		}
	}

	public Stick getShortestStick() {
		if (this.sticks.size() == 0)
			return null;
		Stick shorty = Collections.min(this.sticks);
		return shorty;
	}

	public void cutBySmallestStick() {
		if (this.sticks.size() == 0)
			return;
		Stick shortestStick = this.getShortestStick();
		Integer shortestLength = shortestStick.getLength();
		List<Stick> remainingSticks = new ArrayList<Stick>();
		for (Stick stick : sticks) {
			if (stick.reduceLengthBy(shortestLength) > 0)
				remainingSticks.add(stick);
		}
		this.sticks = remainingSticks;
	}
}

StickCutterTest.java

package com.jamesdaily.study;

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

public class StickCutterTest {

	StickCutter sc;
	final Integer[] stickLengths = { 6, 3, 1, 12, 5, 6, 8, 3, 3, 9, 5, 7, 1 };

	@Before
	public void setUp() throws Exception {

		sc = new StickCutter(stickLengths);
	}

	@Test
	public void testGetShortestStick() {
		Stick shortestStick = sc.getShortestStick();
		assertTrue(1 == shortestStick.getLength());
	}

	@Test
	public void testCutBySmallestStick() {
		System.out.println(sc.getShortestStick().getLength());
		sc.cutBySmallestStick(); // there are now three 2's (formerly 3's)
		System.out.println(sc.sticks.toString());

		assertTrue(sc.sticks.size() == (stickLengths.length - 2));

		System.out.println(sc.getShortestStick().getLength());
		sc.cutBySmallestStick(); // there are not two 1's (formerly 5's)
		System.out.println(sc.sticks.toString());
		assertTrue(sc.sticks.size() == (stickLengths.length - (2 + 3)));

		System.out.println(sc.getShortestStick().getLength());
		sc.cutBySmallestStick();
		System.out.println(sc.sticks.toString());
		assertTrue(sc.sticks.size() == (stickLengths.length - (2 + 3 + 2)));
	}

	@Test
	public void testPileOfOne() {
		final Integer[] oneStickPile = { 6 }; // there are two 1's
		sc = new StickCutter(oneStickPile);

		assertTrue(6 == sc.getShortestStick().getLength());
		System.out.println("Before: " + sc.sticks.toString());
		sc.cutBySmallestStick();
		System.out.println("After: " + sc.sticks.toString());
		assertTrue(sc.sticks.size() == 0); // there are now three 2's (formerly
											// 3's)
		sc.cutBySmallestStick();
		assertTrue(sc.sticks.size() == 0); // still empty
	}

}

StickTest.java

package com.jamesdaily.study;

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

public class StickTest {

	Stick sevenStick;
	Stick fiveStick;

	@Before
	public void setUp() throws Exception {
		sevenStick = new Stick(7);
		fiveStick = new Stick(5);
	}

	@Test
	public void testReduceLengthByInteger() {
		assertTrue((7 - 3) == sevenStick.reduceLengthBy(3));
	}

	@Test
	public void testReduceLengthByStick() {
		assertTrue((7 - 5) == sevenStick.reduceLengthBy(fiveStick));
	}

	@Test
	public void testReduceLengthByLongerStick() {
		try {
			fiveStick.reduceLengthBy(sevenStick);
			fail("Should have thrown!");
		} catch (IllegalArgumentException e) {
		}
	}

	// @Test
	public void testCompareTo() {

	}

}