// Page 244-245

import java.util.LinkedList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;

public class Prog_15_1
{
	public static void main(String[] args)
	{
		Scanner kb = new Scanner(System.in);
		boolean go = true;
		String answer;
		String str;
		LinkedList<String>list = new LinkedList<String>();
		Comparator<String>comparator = Collections.reverseOrder();
		while(go)
		{
			menu();
			answer = kb.next();
			if(answer.equalsIgnoreCase("p"))
			{
				System.out.print("\nPush a string: ");
				str = kb.next();
				list.push(str);
			}
			else if(answer.equalsIgnoreCase("o"))
			{
				System.out.print("\nWill pop the top node");
				list.pop();
			}
			else if(answer.equalsIgnoreCase("s"))
			{
				System.out.print("\nThe List is: " + list);
				System.out.println("\n");
			}
			else if(answer.equalsIgnoreCase("a"))
			{
				System.out.print("\nTo ascending order.");
				Collections.sort(list);
				System.out.print("\nDone the sort.");
			}
			else if(answer.equalsIgnoreCase("d"))
			{
				System.out.print("\nTo descending order.");
				Collections.sort(list, comparator);
				System.out.print("\nDone the sort.");
			}
			else if(answer.equalsIgnoreCase("q"))
				go = false;
		}
	}
	public static void menu()
	{
		System.out.println("\n\n-------------------------");
		System.out.println("P Push an item");
		System.out.println("O Pop an item");
		System.out.println("S Show the list");
		System.out.println("A To ascending order");
		System.out.println("D To descending order");
		System.out.println("Q Quit");
		System.out.println("-------------------------\n\n");
	}
}