CocktailSort.java

// Java program for implementation of Cocktail Sort
public class CocktailSort 
{
	void cocktailSort(int a[])
	{
		boolean swapped = true;
		int start = 0;
		int end = a.length;

		while (swapped == true) 
		{
			// reset the swapped flag on entering the
			// loop, because it might be true from a
			// previous iteration.
			swapped = false;

			// loop from bottom to top same as
			// the bubble sort.
			for (int i = start; i < end - 1; ++i) 
			{
				if (a[i] > a[i + 1]) {
					int temp = a[i];
					a[i] = a[i + 1];
					a[i + 1] = temp;
					swapped = true;
				}
			}

			// if nothing moved, then array is sorted.
			if (swapped == false)
				break;

			// otherwise, reset the swapped flag so that it
			// can be used in the next stage
			swapped = false;

			// move the end point back by one, because
			// item at the end is in its rightful spot
			end = end - 1;

			// from top to bottom, doing the
			// same comparison as in the previous stage
			for (int i = end - 1; i >= start; i--) 
			{
				if (a[i] > a[i + 1]) 
				{
					int temp = a[i];
					a[i] = a[i + 1];
					a[i + 1] = temp;
					swapped = true;
				}
			}

			// increase the starting point, because
			// the last stage would have moved the next
			// smallest number to its rightful spot.
			start = start + 1;
		}
	}

	/* Prints the array */
	void printArray(int a[])
	{
		int n = a.length;
		for (int i = 0; i < n; i++)
			System.out.print(a[i] + " ");
		System.out.println();
	}

	// Driver code
	public static void main(String[] args)
	{
		CocktailSort ob = new CocktailSort();
		int a[] = { 5, 1, 4, 2, 8, 0, 2 };
		ob.cocktailSort(a);
		System.out.println("Sorted array");
		ob.printArray(a);
	}
}