Cocktail Sort

[omfgz]

Hi, i was wondering i some one could show me how does a cocktail sort works in java. i need to sort an array list alphabetically any help would be nice ty

[ComputerJy]

I read the documentation from Wikipedia about the Cocktail Sort and tried my best

import java.util.Random;

public class Test
{
	public static void cocktailSort(final int[] array)
	{
		boolean swapped = false;
		do
		{
			for (int i = 0; i < array.length - 2; i++)
				if (array[i] > array[i + 1])
				{
					Test.swap(array, i);
					swapped = true;
				}
			if (!swapped)
				break;
			swapped = false;
			for (int i = array.length - 2; i >= 0; i--)
				if (array[i] > array[i + 1])
				{
					Test.swap(array, i);
					swapped = true;
				}
		} while (swapped);
	}

	public static void main(final String[] args) throws InterruptedException
	{
		final Random rand = new Random();
		final int[] testArray = new int[rand.nextInt(1000)];
		for (int i = 0; i < testArray.length; i++)
			testArray[i] = rand.nextInt();
		Test.printArray(testArray);
		Thread.sleep(30000);
		Test.cocktailSort(testArray);
		Test.printArray(testArray);
	}

	private static void printArray(final int[] array)
	{
		for (int i = 0; i < array.length; i++)
		{
			System.out.print(array[i]);
			if (i == array.length - 1)
				System.out.println();
			else
				System.out.print(',');
		}
	}

	private static void swap(final int[] array, final int index)
	{
		final int temp = array[index];
		array[index] = array[index + 1];
		array[index + 1] = temp;
	}
}

[ComputerJy]

2 things though, I restricted the size of the array to something less than 1000 so I don't get the OutOfMemory exception. And I added the Thread.sleep for 30 seconds because IO operations are so slow, so the array might be sorted before it's done printing it.

[omfgz]

that kinda makes sense but i have to do it with ArrayList not Array i found it difficult to change positions ...i would really appreciate if you could show me how to do it with arraylists

[ComputerJy]

Same algorithm, ArrayList

import java.util.ArrayList;
import java.util.Random;

public class Test
{
	public static void cocktailSort(final ArrayList<Integer> list)
	{
		boolean swapped = false;
		do
		{
			for (int i = 0; i < list.size() - 2; i++)
				if (list.get(i) > list.get(i + 1))
				{
					Test.swap(list, i);
					swapped = true;
				}
			if (!swapped)
				break;
			swapped = false;
			for (int i = list.size() - 2; i >= 0; i--)
				if (list.get(i) > list.get(i + 1))
				{
					Test.swap(list, i);
					swapped = true;
				}
		} while (swapped);
	}

	public static void main(final String[] args) throws InterruptedException
	{
		final Random rand = new Random();
		final ArrayList<Integer> testList = new ArrayList<Integer>();
		for (int i = 0; i < 1000; i++)
			testList.add(rand.nextInt());
		Test.printList(testList);
		Thread.sleep(10000);
		Test.cocktailSort(testList);
		Test.printList(testList);
	}

	private static void printList(final ArrayList<Integer> list)
	{
		for (int i = 0; i < list.size(); i++)
		{
			System.out.print(list.get(i));
			if (i == list.size() - 1)
				System.out.println();
			else
				System.out.print(", ");
		}
	}

	private static void swap(final ArrayList<Integer> list, final int index)
	{
		final int temp = list.get(index);
		list.set(index, list.get(index + 1));
		list.set(index + 1, temp);
	}
}

[omfgz]

whats Test? in code above?

[ComputerJy]

The name of the class !! :S