EECS2030 Test 4

Programming question

Implement the WordPuzzle class. A skeleton can be found here. The API can be found here. A jar with the Lock class can be found here.

• You have to put your WordPuzzle class in the test4 package.
• You have to implement inheritance and composition.

package test4;

import java.util.HashSet;
import java.util.Set;
import java.util.TreeSet;

/**
 * A word puzzle is a special kind of puzzle.  Each word puzzle
 * has a collection of words.  The word puzzle and its collection
 * of words form a composition.
 *
 */
public class WordPuzzle extends Puzzle 
{
    private Set<String> words;
    
    /**
     * Initializes this word puzzle to be easy and have the given 
     * collection of words.
     * 
     * @param words the collection of words of this word puzzle.
     * @pre. words != null
     */
    public WordPuzzle(Set<String> words)
    {
	super();
	this.setWords(words);
    }

    /**
     * Returns the collection of words of this word puzzle.
     * 
     * @return the collection of words of this word puzzle.
     */
    public Set<String> getWords() 
    {
	return new HashSet<String>(this.words);
    }

    /**
     * Sets the collection of words of this word puzzle to
     * the given collection.
     * 
     * @param words the new collection of words of this word puzzle.
     * @pre. words != null
     */
    public void setWords(Set<String> words) 
    {
	this.words = new HashSet<String>(words);
    }
    
    /**
     * Returns the number of words of this word puzzle.
     * 
     * @return the number of words of this word puzzle.
     */
    public int numberOfWords()
    {
	return this.getWords().size();
    }
    
    /**
     * Returns a string representation of this word puzzle.
     * For example, an easy word puzzle with the words test,
     * awesome and question is represented as
     * "Easy puzzle: awesome question test"
     * 
     * @return "Easy puzzle: ", "Intermediate puzzle: " or "Difficult puzzle: ",
     * depend of the level of this puzzle followed by the words of this
     * word puzzle sorted lexicographically (as in a dictionary).
     */
    public String toString()
    {
	StringBuffer representation = new StringBuffer(super.toString());
	representation.append(":");
	for (String word : new TreeSet<String>(this.getWords()))
	{
	    representation.append(" ");
	    representation.append(word);
	}
	return representation.toString();
    }
}

Other questions

public class CreditCard
{
   private double balance;

   /**
    * Tests whether the balance of this card is positive.
    *
    * @return true if the balance of this card is positive, false otherwise.
    */
   public boolean positive()
   {
      return this.balance > 0;
   }
}

public class RewardCard extends CreditCard
{
   private int points;

   /**
    * Tests whether the balance or the points balance of this card is positive.
    *
    * @return true if the balance or the points balance of this card is positive, false otherwise.
    */
   public boolean positive()
   {
      return super.positive() || this.points > 0;
   }
}