Elevens Activity 7
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Questions
1.What items would be necessary if you were playing a game of Elevens at your desk (not on the computer)? List the private instance variables needed for the ElevensBoard class.
2. What items would be necessary if you were playing a game of Elevens at your desk (not on the computer)? List the private instance variables needed for the ElevensBoard class. Write an algorithm that describes the actions necessary to play the Elevens game.
3. Now examine the partially implemented ElevensBoard.java file found in the Activity7 Starter Code directory. Does the ElevensBoard class contain all the state and behavior necessary to play the game?
4. ElevensBoard.java contains three helper methods. These helper methods are private because they are only called from the ElevensBoard class.
4a. Where is the dealMyCards method called in ElevensBoard?
4b. Which public methods should call the containsPairSum11 and containsJQK methods?
4c. It’s important to understand how the cardIndexes method works, and how the list that it returns is used. Suppose that cards contains the elements shown below. Trace the execution of the cardIndexes method to determine what list will be returned. Complete the diagram below by filling in the elements of the returned list, and by showing how those values index cards. Note that the returned list may have less than 9 elements.
4d code: Complete the following printCards method to print all of the elements of cards that are indexed by cIndexes.
public static printCards(ElevensBoard board) { List<Integer> cIndexes = board.cardIndexes();
/* Your code goes here. */
4e. Which one of the methods that you identified in question 4b above needs to call the cardIndexes method before calling the containsPairSum11 and containsJQK methods? Why?
ElevensBoard.java
import java.util.List;
import java.util.ArrayList;
/**
* The ElevensBoard class represents the board in a game of Elevens.
*/
public class ElevensBoard {
/**
* The size (number of cards) on the board.
*/
private static final int BOARD_SIZE = 9;
/**
* The ranks of the cards for this game to be sent to the deck.
*/
private static final String[] RANKS =
{"ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "jack", "queen", "king"};
/**
* The suits of the cards for this game to be sent to the deck.
*/
private static final String[] SUITS =
{"spades", "hearts", "diamonds", "clubs"};
/**
* The values of the cards for this game to be sent to the deck.
*/
private static final int[] POINT_VALUES =
{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 0, 0};
/**
* The cards on this board.
*/
private Card[] cards;
/**
* The deck of cards being used to play the current game.
*/
private Deck deck;
/**
* Flag used to control debugging print statements.
*/
private static final boolean I_AM_DEBUGGING = false;
/**
* Creates a new <code>ElevensBoard</code> instance.
*/
public ElevensBoard() {
cards = new Card[BOARD_SIZE];
deck = new Deck(RANKS, SUITS, POINT_VALUES);
if (I_AM_DEBUGGING) {
System.out.println(deck);
System.out.println("----------");
}
dealMyCards();
}
/**
* Start a new game by shuffling the deck and
* dealing some cards to this board.
*/
public void newGame() {
deck.shuffle();
dealMyCards();
}
/**
* Accesses the size of the board.
* Note that this is not the number of cards it contains,
* which will be smaller near the end of a winning game.
* @return the size of the board
*/
public int size() {
return cards.length;
}
/**
* Determines if the board is empty (has no cards).
* @return true if this board is empty; false otherwise.
*/
public boolean isEmpty() {
for (int k = 0; k < cards.length; k++) {
if (cards[k] != null) {
return false;
}
}
return true;
}
/**
* Deal a card to the kth position in this board.
* If the deck is empty, the kth card is set to null.
* @param k the index of the card to be dealt.
*/
public void deal(int k) {
cards[k] = deck.deal();
}
/**
* Accesses the deck's size.
* @return the number of undealt cards left in the deck.
*/
public int deckSize() {
return deck.size();
}
/**
* Accesses a card on the board.
* @return the card at position k on the board.
* @param k is the board position of the card to return.
*/
public Card cardAt(int k) {
return cards[k];
}
/**
* Replaces selected cards on the board by dealing new cards.
* @param selectedCards is a list of the indices of the
* cards to be replaced.
*/
public void replaceSelectedCards(List<Integer> selectedCards) {
for (Integer k : selectedCards) {
deal(k.intValue());
}
}
/**
* Gets the indexes of the actual (non-null) cards on the board.
*
* @return a List that contains the locations (indexes)
* of the non-null entries on the board.
*/
public List<Integer> cardIndexes() {
List<Integer> selected = new ArrayList<Integer>();
for (int k = 0; k < cards.length; k++) {
if (cards[k] != null) {
selected.add(new Integer(k));
}
}
return selected;
}
/**
* Generates and returns a string representation of this board.
* @return the string version of this board.
*/
public String toString() {
String s = "";
for (int k = 0; k < cards.length; k++) {
s = s + k + ": " + cards[k] + "\n";
}
return s;
}
/**
* Determine whether or not the game has been won,
* i.e. neither the board nor the deck has any more cards.
* @return true when the current game has been won;
* false otherwise.
*/
public boolean gameIsWon() {
if (deck.isEmpty()) {
for (Card c : cards) {
if (c != null) {
return false;
}
}
return true;
}
return false;
}
/**
* Determines if the selected cards form a valid group for removal.
* In Elevens, the legal groups are (1) a pair of non-face cards
* whose values add to 11, and (2) a group of three cards consisting of
* a jack, a queen, and a king in some order.
* @param selectedCards the list of the indices of the selected cards.
* @return true if the selected cards form a valid group for removal;
* false otherwise.
*/
public boolean isLegal(List<Integer> selectedCards) {
/* *** TO BE IMPLEMENTED IN ACTIVITY 9 *** */
}
/**
* Determine if there are any legal plays left on the board.
* In Elevens, there is a legal play if the board contains
* (1) a pair of non-face cards whose values add to 11, or (2) a group
* of three cards consisting of a jack, a queen, and a king in some order.
* @return true if there is a legal play left on the board;
* false otherwise.
*/
public boolean anotherPlayIsPossible() {
/* *** TO BE IMPLEMENTED IN ACTIVITY 9 *** */
}
/**
* Deal cards to this board to start the game.
*/
private void dealMyCards() {
for (int k = 0; k < cards.length; k++) {
cards[k] = deck.deal();
}
}
/**
* Check for an 11-pair in the selected cards.
* @param selectedCards selects a subset of this board. It is list
* of indexes into this board that are searched
* to find an 11-pair.
* @return true if the board entries in selectedCards
* contain an 11-pair; false otherwise.
*/
private boolean containsPairSum11(List<Integer> selectedCards) {
/* *** TO BE IMPLEMENTED IN ACTIVITY 9 *** */
}
/**
* Check for a JQK in the selected cards.
* @param selectedCards selects a subset of this board. It is list
* of indexes into this board that are searched
* to find a JQK group.
* @return true if the board entries in selectedCards
* include a jack, a queen, and a king; false otherwise.
*/
private boolean containsJQK(List<Integer> selectedCards) {
/* *** TO BE IMPLEMENTED IN ACTIVITY 9 *** */
}
}
Card.java
/**
* Card.java
*
* <code>Card</code> represents a playing card.
*/
public class Card {
/**
* String value that holds the suit of the card
*/
private String suit;
/**
* String value that holds the rank of the card
*/
private String rank;
/**
* int value that holds the point value.
*/
private int pointValue;
/**
* Creates a new <code>Card</code> instance.
*
* @param cardRank a <code>String</code> value
* containing the rank of the card
* @param cardSuit a <code>String</code> value
* containing the suit of the card
* @param cardPointValue an <code>int</code> value
* containing the point value of the card
*/
public Card(String cardRank, String cardSuit, int cardPointValue) {
//initializes a new Card with the given rank, suit, and point value
rank = cardRank;
suit = cardSuit;
pointValue = cardPointValue;
}
/**
* Accesses this <code>Card's</code> suit.
* @return this <code>Card's</code> suit.
*/
public String suit() {
return suit;
}
/**
* Accesses this <code>Card's</code> rank.
* @return this <code>Card's</code> rank.
*/
public String rank() {
return rank;
}
/**
* Accesses this <code>Card's</code> point value.
* @return this <code>Card's</code> point value.
*/
public int pointValue() {
return pointValue;
}
/** Compare this card with the argument.
* @param otherCard the other card to compare to this
* @return true if the rank, suit, and point value of this card
* are equal to those of the argument;
* false otherwise.
*/
public boolean matches(Card otherCard) {
return otherCard.suit().equals(this.suit())
&& otherCard.rank().equals(this.rank())
&& otherCard.pointValue() == this.pointValue();
}
/**
* Converts the rank, suit, and point value into a string in the format
* "[Rank] of [Suit] (point value = [PointValue])".
* This provides a useful way of printing the contents
* of a <code>Deck</code> in an easily readable format or performing
* other similar functions.
*
* @return a <code>String</code> containing the rank, suit,
* and point value of the card.
*/
@Override
public String toString() {
return rank + " of " + suit + " (point value = " + pointValue + ")";
}
}
Deck.java
import java.util.List;
import java.util.ArrayList;
/**
* The Deck class represents a shuffled deck of cards.
* It provides several operations including
* initialize, shuffle, deal, and check if empty.
*/
public class Deck {
/**
* cards contains all the cards in the deck.
*/
private List<Card> cards;
/**
* size is the number of not-yet-dealt cards.
* Cards are dealt from the top (highest index) down.
* The next card to be dealt is at size - 1.
*/
private int size;
/**
* Creates a new <code>Deck</code> instance.<BR>
* It pairs each element of ranks with each element of suits,
* and produces one of the corresponding card.
* @param ranks is an array containing all of the card ranks.
* @param suits is an array containing all of the card suits.
* @param values is an array containing all of the card point values.
*/
public Deck(String[] ranks, String[] suits, int[] values) {
cards = new ArrayList<Card>();
for (int j = 0; j < ranks.length; j++) {
for (String suitString : suits) {
cards.add(new Card(ranks[j], suitString, values[j]));
}
}
size = cards.size();
shuffle();
}
/**
* Determines if this deck is empty (no undealt cards).
* @return true if this deck is empty, false otherwise.
*/
public boolean isEmpty() {
return size == 0;
}
/**
* Accesses the number of undealt cards in this deck.
* @return the number of undealt cards in this deck.
*/
public int size() {
return size;
}
/**
* Randomly permute the given collection of cards
* and reset the size to represent the entire deck.
*/
public void shuffle() {
for (int k = cards.size() - 1; k > 0; k--) {
int howMany = k + 1;
int start = 0;
int randPos = (int) (Math.random() * howMany) + start;
Card temp = cards.get(k);
cards.set(k, cards.get(randPos));
cards.set(randPos, temp);
}
size = cards.size();
}
/**
* Deals a card from this deck.
* @return the card just dealt, or null if all the cards have been
* previously dealt.
*/
public Card deal() {
if (isEmpty()) {
return null;
}
size--;
Card c = cards.get(size);
return c;
}
/**
* Generates and returns a string representation of this deck.
* @return a string representation of this deck.
*/
@Override
public String toString() {
String rtn = "size = " + size + "\nUndealt cards: \n";
for (int k = size - 1; k >= 0; k--) {
rtn = rtn + cards.get(k);
if (k != 0) {
rtn = rtn + ", ";
}
if ((size - k) % 2 == 0) {
// Insert carriage returns so entire deck is visible on console.
rtn = rtn + "\n";
}
}
rtn = rtn + "\nDealt cards: \n";
for (int k = cards.size() - 1; k >= size; k--) {
rtn = rtn + cards.get(k);
if (k != size) {
rtn = rtn + ", ";
}
if ((k - cards.size()) % 2 == 0) {
// Insert carriage returns so entire deck is visible on console.
rtn = rtn + "\n";
}
}
rtn = rtn + "\n";
return rtn;
}
}