Question

Programming Language: Java

1. Write a class called Pair that stores a pair of numbers in private fields. Include a two-arg constructor, mutators and accessors. Override the equals method so that a Pair (1,2) would be considered equal to Pair (2,1). Write an appropriate toString method and make the toString method non-overrideable.

2. Write an interface called Comparable that includes a method isGreater, isLesser, and isSame. These methods should each take a Pair object as a parameter.

3. Write an interface called Nameable that includes method setName and method getName.

4. Write a child class of Pair called GoodPair that implements the two interfaces above. The isSame method should consider Pair (1,2) to be the same as Pair (1,2) but not the same as Pair (2,1). You can interpret isGreater as returning true if the sum of the two elements of a pair is greater than the sum of the two element of the other pair that it is being compared to, and you can interpret isLesser similarly.

Use the following code in the demo class:

public static void main(String[] args)
{
       Pair pairA = new Pair(2, 1);
       Pair pairB = new Pair(1, 2);
       System.out.println("The pair A = " + pairA + "\nThe pair B = " + pairB);
       if(pairA.equals(pairB))
           System.out.println("The pair A is equal to pair B.");
       else
           System.out.println("The pair A is NOT equal to pair B.");

       GoodPair gPairA = new GoodPair(2, 1);
       GoodPair gPairB = new GoodPair(1, 2);
       System.out.println("The good pair A = " + pairA + "\nThe good pair B = " + pairB);
       if(gPairA.isSame(gPairB))
           System.out.println("The good pair A is the same as good pair B.");
       else
           System.out.println("The good pair A is NOT the same as good pair B.");

       if(gPairA.isGreater(gPairB))
           System.out.println("The good pair A is greater than good pair B.");
       else
           System.out.println("The good pair A is NOT greater than good pair B.");
}

Answer 1

Thanks for the question. Below is the code you will be needing. Let me know if you have any doubts or if you need anything to change. 

If you are satisfied with the solution, please rate the answer.

Thank You !

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public class Pair {

    private int x;
    private int y;

    public Pair(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Pair pair = (Pair) o;
        return x == pair.x &&
                y == pair.y;
    }
    

    @Override
    public String toString() {
        return "(" + x + "," + y + ")";
    }

    public static void main(String[] args) {
        Pair pairA = new Pair(2, 1);
        Pair pairB = new Pair(1, 2);
        System.out.println("The pair A = " + pairA + "\nThe pair B = " + pairB);
        if (pairA.equals(pairB))
            System.out.println("The pair A is equal to pair B.");
        else
            System.out.println("The pair A is NOT equal to pair B.");

        GoodPair gPairA = new GoodPair(2, 1);
        GoodPair gPairB = new GoodPair(1, 2);
        System.out.println("The good pair A = " + pairA + "\nThe good pair B = " + pairB);
        if (gPairA.isSame(gPairB))
            System.out.println("The good pair A is the same as good pair B.");
        else
            System.out.println("The good pair A is NOT the same as good pair B.");

        if (gPairA.isGreater(gPairB))
            System.out.println("The good pair A is greater than good pair B.");
        else
            System.out.println("The good pair A is NOT greater than good pair B.");
    }
}

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public interface Comparable {

    public boolean isGreater(Pair pair);
    public boolean isLesser(Pair pair);
    public boolean isSame(Pair pair);
}

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public interface Nameable {

    public void setName(String name);
    public void getName();
}

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public class GoodPair extends Pair implements Comparable,Nameable {


    public GoodPair(int x, int y) {
        super(x, y);
    }

    @Override
    public boolean isGreater(Pair pair) {
        return (getY()+getX())>(pair.getY()+pair.getX());
    }

    @Override
    public boolean isLesser(Pair pair) {
        return (getY()+getX())<(pair.getY()+pair.getX());
    }

    @Override
    public boolean isSame(Pair pair) {
        return getX()==pair.getX() && getY()==pair.getY();
    }

    @Override
    public void setName(String name) {

    }

    @Override
    public void getName() {

    }
}

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