import java.util.ArrayDeque;

public class DequeTestProgram {
	private static int UNDO_LIST_CAPACITY = 5;

	private static ArrayDeque<String>	operations;

	private static void performOperation(String x) {
		if (operations.size() == UNDO_LIST_CAPACITY)
			operations.removeFirst();
		operations.addLast(x);
	}
	private static void undo() {
		operations.removeLast();
	}

	public static void main(String[] args) {
		operations = new ArrayDeque<String>();
		System.out.println("Simulating some cut/paste/move operations ... ");
		performOperation("cut1");
		performOperation("paste1");
		performOperation("move1");
		System.out.println("Here is the undo list now: " + operations);

		System.out.println("Simulating an undo operation ...");
		undo();
		System.out.println("Here is the undo list now: " + operations);

		System.out.println("Simulating another undo operation ...");
		undo();
		System.out.println("Here is the undo list now: " + operations);

		System.out.println("Simulating some more cut/paste/move operations ... ");
		performOperation("cut2");
		performOperation("paste2");
		performOperation("move2");
		performOperation("move3");
		System.out.println("Here is the undo list now: " + operations);

		System.out.println("Simulating some more paste operations ... ");
		performOperation("paste3");
		performOperation("paste4");

		System.out.println("Here is the undo list now: " + operations);
    }
}