Question

You need to complete the methods getSmallerValue, getLargerValue, compareTo, and equals.

Must pass these tests: Test that each domino is smaller than every domino after it in the list (compareTo method). - Test that each domino is greater than every domino before it in the list (compareTo method). - Tests if three dominoes with the same values are equal (equal method).

Code:

public class Domino implements Comparable<Domino> {

/**

* The smallest possible value for a side of a domino.

*/

public static final int MIN_VALUE = 0;

/**

* The largest possible value for a side of a domino.

*/

public static final int MAX_VALUE = 6;

/**

* The two values on the domino.

*/

private int val1;

private int val2;

public Domino() {

this(0, 0);

}

public Domino(int value1, int value2) {

if (!isValueOK(value1) || !isValueOK(value2)) {

throw new IllegalArgumentException();

}

this.val1 = value1;

this.val2 = value2;

}

public Domino(Domino other) {

this(other.val1, other.val2);

}

private static boolean isValueOK(int value) {

return value >= MIN_VALUE && value <= MAX_VALUE;

}

@Override

public int hashCode() {

return this.getSmallerValue() + 11 * this.getLargerValue();

}

@Override

public String toString() {

return "[" + this.getSmallerValue() + " : " + this.getLargerValue() + "]";

}

/*

* You need to implement the four methods below. Both compareTo and equals

* should make use of getSmallerValue and getLargerValue.

*/

public int getSmallerValue() {

}

public int getLargerValue() {

}

@Override

public int compareTo(Domino other) {

}

@Override

public boolean equals(Object obj) {

}

}

Answer 1

// Domino.java

public class Domino implements Comparable<Domino>{

      

       /**

       * The smallest possible value for a side of a domino.

       */

       public static final int MIN_VALUE = 0;

       /**

       * The largest possible value for a side of a domino.

       */

       public static final int MAX_VALUE = 6;

      

       /**

       * The two values on the domino.

       */

       private int val1;

       private int val2;

      

       public Domino() {

             this(0, 0);

             }

             public Domino(int value1, int value2) {

             if (!isValueOK(value1) || !isValueOK(value2)) {

             throw new IllegalArgumentException();

             }

             this.val1 = value1;

             this.val2 = value2;

             }

             public Domino(Domino other) {

             this(other.val1, other.val2);

             }

            

             private static boolean isValueOK(int value) {

                    return value >= MIN_VALUE && value <= MAX_VALUE;

                    }

                    @Override

                    public int hashCode() {

                    return this.getSmallerValue() + 11 * this.getLargerValue();

                    }

                    @Override

                    public String toString() {

                    return "[" + this.getSmallerValue() + " : " + this.getLargerValue() + "]";

                    }

                    /*

                    * You need to implement the four methods below. Both compareTo and equals

                    * should make use of getSmallerValue and getLargerValue.

                    */

                    public int getSmallerValue() {

                          

                           if(val1 < val2) // if val1 < val2 , return val1

                                 return val1;

                           return val2; // val2 <= val1

                    }

                    public int getLargerValue() {

                          

                           if(val1 > val2) // if val1 > val2, return val1

                                 return val1;

                           return val2; // val2 >= val1

                    }

                    @Override

                    public int compareTo(Domino other) {

                           // if larger value of this domino > larger value of other domino then return 1

                           if(getLargerValue() > other.getLargerValue())

                                 return 1;

                           // if larger value of this domino < larger value of other domino then return -1

                           else if(getLargerValue() < other.getLargerValue())

                                 return -1;

                           else // if larger values of this and other domino are equal

                           {

                                 // if smaller value of this domino > smaller value of other domino then return 1

                                 if(getSmallerValue() > other.getSmallerValue())

                                        return 1;

                                 // if smaller value of this domino < smaller value of other domino then return -1

                                 else if(getSmallerValue() < other.getSmallerValue())

                                        return -1;

                                 else // smaller values of this and other domino are equal , return 0 (both domino are equal)

                                        return 0;

                           }

                    }

                    @Override

                    public boolean equals(Object obj) {

                          

                           // check if obj is an instance of Domino class

                           if(obj instanceof Domino)

                           {

                                 Domino other = (Domino)obj; // cast obj to Domino

                                 // Both dominoes are equal only if there larger and smaller values are equal

                                 return((getLargerValue() == other.getLargerValue()) &&

                                               getSmallerValue() == other.getSmallerValue());

                           }

                          

                           return false; // obj is not an instance of Domino

                    }

}

//end of Domino.java