//LinkedListTest.java
//exact same as ArrayListTest.java
//did global replace of ArrayList with LinkedList

//LinkedList is almost the same as ArrayList.
//The difference is that it is implemented by a linked list instead of an
//array like ArrayList and so compared to ArrayList it is:
//    faster insert/delete (if location to insert or delete is already known),
//      insert/delete at either end is very fast and so the LinkedList is good
//      for a stack or queue.
//    slightly slower iteration.???
//    much slower random access (using an index).
//Methods are the same as ArrayList.  It has some additional ones for inserting
//and deleting at the beginning and end of the list but these can be done by
//get, add, and remove methods.
//  http://java.sun.com/j2se/1.5.0/docs/api/java/util/LinkedList.html

import java.util.*;         //all the Collections Framework classes are here
import javax.swing.*;

class LinkedListTest {
    public static void main(String[] args) {
	String input, userstring;
	int size;
	int range;
	int randInt;
	int userAnswer;
	
        //indexed list of (any kind of) objects (but not primitives).
        //size expands as needed
	LinkedList myLinkedList = new LinkedList();  
	
	input = JOptionPane.showInputDialog( "Enter number of random ints to generate" );
	size = Integer.parseInt( input );

	input = JOptionPane.showInputDialog( "Enter upper range of the random ints" );
	range = Integer.parseInt( input );

	for (int i=1; i<=size; i++) {   //i is not an index, just a loop counter
	    randInt = (int)(Math.random()*range);  //random int between 0 and range-1
	    //uncomment if this code confuses you:
	    //System.out.println("generated int: " + randInt);
	    myLinkedList.add(new Integer(randInt));  //must wrap int into Integer
	}

	//iterate over all the objects in the arraylist collection.
	Iterator it=myLinkedList.iterator();
	//an iterator is for accessing all the objects of collection, one by one.
	//hasNext() is true until reach end of the collection.
	//next()  returns the next object in the iteration.
	//notice no for loop looping over indexes!
	System.out.println("Here are your random integers: ");
	while (it.hasNext())
	    //display them on one line, separated by a blank
	    System.out.print(it.next() + " ");    
	System.out.println();


	//is this cool or what?
	//now get strings from the user into an arraylist.  
	//we should use another arraylist but I want to show that anythings
	//can be in an arraylist. 
	myLinkedList.clear();     //remove all the previous contents
	
	input = JOptionPane.showInputDialog( "Enter number of strings you want to input" );
	size = Integer.parseInt( input );

	for (int i=1; i<=size; i++) {  
	    userstring = JOptionPane.showInputDialog( "Enter string #" + i );
	    myLinkedList.add(userstring);  
	}
	
	//must re-initialize the iterator
	it=myLinkedList.iterator();
	System.out.println();
	System.out.println("Here are your strings: ");
	while (it.hasNext())
	    System.out.print(it.next() + " ");    
	System.out.println();
	
	System.out.println(" there are " + myLinkedList.size() + 
		           " objects in the arraylist");
	if (myLinkedList.isEmpty())
           System.out.println(" the arraylist is empty");
	else
           System.out.println(" the arraylist is not empty (duhh)");
           


//some of the algorithms of the Collections class
	userAnswer = JOptionPane.showConfirmDialog(null,
						   "Do you want to sort the list?",
						   "Sort 'em?",
						   JOptionPane.YES_NO_OPTION);
	if (userAnswer == JOptionPane.YES_OPTION) {
	    Collections.sort(myLinkedList);  //static method of Collections class
            it=myLinkedList.iterator();
	    System.out.println();
	    System.out.println("Here are your sorted strings: ");
	    while (it.hasNext())
	        System.out.print(it.next() + " ");    
	    System.out.println();
	}


	userAnswer = JOptionPane.showConfirmDialog(null,
						   "Do you want to reverse the list?",
						   "Reverse 'em?",
						   JOptionPane.YES_NO_OPTION);
	if (userAnswer == JOptionPane.YES_OPTION) {
	    Collections.reverse(myLinkedList);  //static method of Collections class
            it=myLinkedList.iterator();
	    System.out.println();
	    System.out.println("Here are your reversed strings: ");
	    while (it.hasNext())
	        System.out.print(it.next() + " ");    
	    System.out.println();
	}

	userAnswer = JOptionPane.showConfirmDialog(null,
						   "Do you want to shuffle the list?",
						   "Shuffle 'em?",
						   JOptionPane.YES_NO_OPTION);
	if (userAnswer == JOptionPane.YES_OPTION) {
	    Collections.shuffle(myLinkedList);  //static method of Collections class
            it=myLinkedList.iterator();
	    System.out.println();
	    System.out.println("Here are your shuffled strings: ");
	    while (it.hasNext())
	        System.out.print(it.next() + " ");    
	    System.out.println();
	}

	
        System.out.println("Min value in arraylist: " + Collections.min(myLinkedList));
        System.out.println("Max value in arraylist: " + Collections.max(myLinkedList));


    }
}