Java program question: (this is a buildup from a previous prommaing assigment but I have the code to the previous one)

What I have:

import java.util.Random;

public class ArrayBag implements Bag

{

public static final int DEFAULT_CAPACITY = 10;

private T [] collection;

private int size;

/*

* default constructor * * bag initially set to 10 items */

public ArrayBag()

{

this(DEFAULT_CAPACITY);

}

/*

* argument constructor * size of bag specified by user */

@SuppressWarnings("unchecked")

public ArrayBag(int capacity)

{

if (capacity

{

throw new IllegalArgumentException("bag can't be negative size!");

}

collection = (T []) new Object [capacity];

size = 0;

}

/* * adds item to bag * if at capacity, bag is resized */

public void add (T item)

{

checkForNull(item);

ensureSpace();

collection[size] = item;

size++;

}

/*

* removes item from bag * returns removed item */

public T remove ()

{

if (size == 0)

{

return null;

}

T removed = collection[size-1];

collection[size-1] = null;

size--;

return removed;

}

/* * returns item from bag */

public T get()

{

if (size == 0)

{

return null;

}

return collection[size-1];

}

/* * returns true if item is in bag, false otherwise */

public boolean contains(T item)

{

for (int i = 0; i

{

if (collection[i].equals(item))

{

return true;

}

}

return false;

}

/* * returns size of bag */

public int size()

{

return size;

}

/* * returns string representation of contents of bag */

public String toString()

{

String s = "[";

for (int i = 0; i

{

s+= collection[i];

if (i

{

s+= ", ";

}

}

return s + "]";

}

/* methods to be added */ /* * removes specified item from bag * * returns false if item not present */

public boolean remove (T item)

{

for(int i=0; i

{

if(item.equals(collection[i]))

{

for(int j=i; j

{

collection[j] = collection[j+1];

}

collection[size-1] = null;

size--;

return true;

}

}

return false;

}

/* * removes random item from bag * returns null if bag is empty */

public T removeRandom ()

{

if(size == 0)

return null;

T item = collection[new Random().nextInt(size)];

remove(item);

return item;

}

/* * returns random item from bag * returns null if bag is empty */

public T getRandom ()

{

if(size == 0)

return null;

return collection[new Random().nextInt(size)];

}

/* end of added methods */ /* * checks if item is null and throws exception if so */

private void checkForNull (T item)

{

if (item == null)

{

throw new IllegalArgumentException("null not a possible value!");

}

}

/* * doubles size of array if at capacity */ private void ensureSpace()

{

if (size == collection.length)

{

@SuppressWarnings("unchecked")

T [] larger = (T []) new Object [size * 2];

for (int i = 0; i

{

larger[i] = collection[i];

}

collection = larger;

larger = null;

System.out.println("Hi");

}

}

}

public interface Bag { void add (T item); T remove(); T get(); boolean contains (T item); int size(); public String toString();

boolean remove (T item); T removeRandom(); T getRandom(); }

public class Bags { public static void main (String [] args) { try { Bag words = new ArrayBag(); //Bag words = new LinkedBag(); // adding to bag String [] fruits = {"orange", "grape", "kiwi", "coconut", "lime"}; for (int i = 0; i

// seeing if bag contains item boolean result = words.contains("kiwi"); System.out.println(" Does our bag contain the word 'kiwi'? " + (result ? "yes" : "no")); result = words.contains("mango"); System.out.println("Does our bag contain the word 'mango'? " + (result ? "yes" : "no")); // retrieving item System.out.println(" Selecting an item (always same)"); System.out.println(words.get()); System.out.println(words.get());

// retrieving random item System.out.println(" Selecting a random item (varies)"); System.out.println(words.getRandom()); System.out.println(words.getRandom());

// removing specific item words.remove("grape"); System.out.println(" Removing 'grape' from the bag " + words); // removing item System.out.println(" Removing an item (always end one)"); System.out.println(words.remove()); System.out.println(words);

// removing random item System.out.println(" Removing a random item"); System.out.println(words.removeRandom()); System.out.println(words + " ");

// testing methods on empty bag System.out.println("Let's empty the bag"); words.remove(); words.remove(); System.out.println(words); System.out.println("Trying to get a random item " + words.getRandom()); System.out.println("Trying to remove a random item " + words.removeRandom()); System.out.println("Trying to remove 'kiwi' " + words.remove("kiwi")); } catch (IllegalArgumentException e) { System.out.println(e.getMessage()); } } }

public class LinkedBag implements Bag { private class Node { private T data; private Node next; public Node(T item) { data = item; next = null; } } private Node head; private int size; public LinkedBag() { head = null; size = 0; } public void add(T item) { checkForNull(item); Node newest = new Node (item); newest.next = head; head = newest; size++; } public T remove() { if (size == 0) return null; T removed = head.data; head = head.next; size--; return removed; } public T get() { if (size == 0) return null; return head.data; } public boolean contains(T item) { Node current = head; for (int i = 0; i  
 
 
 
 
 
 
 
 
/* * WordGame * * beginnings of a Scrabble-like word game * * adds the letter tiles from Scrabble to a bag and randomly selects * seven for the user's hand */ public class WordGame { // number of letters in player's hand in Scrabble public static final int LETTERS_PER_TURN = 7; // distribution of Scrabble tiles public static final char [][] ENGLISH_LETTERS = {{'1', 'K', 'J', 'X', 'Q', 'Z'}, {'2', 'B', 'C', 'M', 'P', 'F', 'H', 'V', 'W', 'Y'}, {'3', 'G'}, {'4', 'L', 'S', 'U', 'D'}, {'6', 'N', 'R', 'T'}, {'8', 'O'}, {'9', 'A', 'I'}, {'0', 'E'}}; /* * adds letter tiles to bag according to their distribution */ public static void addLetters(Bag b, char [] [] let) { // cycle through set of letters for (int i = 0; i  let, Bag player) { } public static void main (String [] args) { // add letters to bag Bag letters = new ArrayBag(); addLetters(letters, ENGLISH_LETTERS); // give player seven random letters Bag playerLetters = new LinkedBag(); selectLetters(letters, playerLetters); System.out.println("Your letters are: " + playerLetters); } } 
  Implement the three methods you wrote for ArrayBag for LinkedBag: boolean remove (T item); T removeRandomO; T getRandomO Then test them using Bags.java. The output will be similar to that for the ArrayBag (but with the order reversed since operations for the linked bag are performed at the front): Here's what's in our bag [lime, coconut, kiwi, grape, orange] Does our bag contain the word 'kiwi'? yes Does our bag contain the word 'mango'? no Selecting an item (always same) lime lime Selecting a random item (varies) coconut grape Removing grape' from the bag [coconut, kiwi, lime, orange] Removing an item (always front one) coconut [kiwi, lime, orange] Removing a random item kiwi [lime, orange]