Question

Create an abstract class DiscountPolicy. It should have a single abstract method computeDiscount that will return the discount for the purchase of a given number of a single item. The method has two parameters, count and itemCost. 2. Derive a class BulkDiscount from DiscountPolicy, as described in the previous exercise. It should have a constructor that has two parameters, minimum and percent. It should define the method computeDiscount so that if the quantity purchased of an item is more than minimum, the discount is percent percent. 3. Derive a class BuyNItemsGetOneFree from DiscountPolicy, as described in Exercise 1. The class should have a constructor that has a single parameter n. In addition, the class should define the method computeDiscount so that every nth item is free. For example, the following table gives the discount for the purchase of various counts of an item that costs $10, when n is 3: count 1 2 3 4 5 6 7 Discount 0 0 10 10 10 20 20
4. Derive a class CombinedDiscount from DiscountPolicy, as described in Exercise 1. It should have a constructor that has two parameters of type DiscountPolicy. It should define the method computeDiscount to return the maximum value returned by computeDiscount for each of its two private discount policies. The two discount policies are described in Exercises 2 and 3. 5. Define DiscountPolicy as an interface instead of the abstract class described in Exercise 1.

Answer 1

Answer:

Java Code was used to define classes in the abstract discount policy,The bulk discount, The buy items get one free and the combined discount

Explanation:

Solution

Code:

Main.java

public class Main {

public static void main(String[] args) {

  BulkDiscount bd=new BulkDiscount(10,5);

BuyNItemsGetOneFree bnd=new BuyNItemsGetOneFree(5);

CombinedDiscount cd=new CombinedDiscount(bd,bnd);

System.out.println("Bulk Discount :"+bd.computeDiscount(20, 20));

  System.out.println("Nth item discount :"+bnd.computeDiscount(20, 20));

 System.out.println("Combined discount :"+cd.computeDiscount(20, 20));    

  }

}

discountPolicy.java

public abstract class DiscountPolicy

{    

public abstract double computeDiscount(int count, double itemCost);

}    

BulkDiscount.java  

public class BulkDiscount extends DiscountPolicy

{    

private double percent;

private double minimum;

public BulkDiscount(int minimum, double percent)

{

this.minimum = minimum;

this.percent = percent;

}

at Override

public double computeDiscount(int count, double itemCost)

{

if (count >= minimum)

{

return (percent/100)*(count*itemCost); //discount is total price * percentage discount

}

return 0;

}

}

BuyNItemsGetOneFree.java

public class BuyNItemsGetOneFree extends DiscountPolicy

{

private int itemNumberForFree;

public BuyNItemsGetOneFree(int n)

{

  itemNumberForFree = n;

}

at Override

public double computeDiscount(int count, double itemCost)

{

if(count > itemNumberForFree)

return (count/itemNumberForFree)*itemCost;

else

  return 0;

}

}

CombinedDiscount.java

public class CombinedDiscount extends DiscountPolicy

{

private DiscountPolicy first, second;

public CombinedDiscount(DiscountPolicy firstDiscount, DiscountPolicy secondDiscount)

{

first = firstDiscount;

second = secondDiscount;

}

at Override

public double computeDiscount(int count, double itemCost)

{

double firstDiscount=first.computeDiscount(count, itemCost);

double secondDiscount=second.computeDiscount(count, itemCost);

if(firstDiscount>secondDiscount){

  return firstDiscount;

}else{

  return secondDiscount;

}

}  

}