Q1)
public class Product {
       private String name;
       private double weight;
       private String manufacturer;

       public Product(String name, double weight, String manufacturer) {
       	      this.name = name;
	      this.weight = weight;
	      this.manufacturer = manufacturer;
       }

       public String getName() {
       	      return this.name;
       }

       public void setName(String newName) {
       	      this.name = newName;
       }

ÃÂ       public double getWeight() {
       	      return this.weight;
       }

       public void setWeight(double weight) { 
       	      this.weight = weight;
       }

       public String getManufacturer() {
       	      return this.manufacturer;
       }

       public void setManufacturer(String newManufacturer) {
       	      this.manufacturer = newManufacturer;
       }
}

Q2)
public class Merchant {
       private String name;
       private String location;
       private boolean isOnline;

       public Merchant(String name, String location, boolean isOnline) {
       	      this.name = name;
	      this.location = location;
	      this.isOnline = isOnline;
       }

       public String getName() {
       	      return this.name;
       }

       public void setName(String newName) {
       	      this.name = newName;
       }

       public String getLocation() {
       	      return this.location;
       }

       public void setLocation(String location) {
       	      this.location = location;
       }

       public boolean getIsOnline() {
       	      return this.isOnline;
       }

       public void setIsOnline(boolean isOnline) {
       	      this.isOnline = isOnline;
       }
}

Q3)
public class Offer{
       private Merchant merchant;
       private Product product;
       private double currentPrice;
       private double normalPrice;
       private boolean limitedSupply;

       public Offer(Merchant m, Product p, double cp, double np, boolean limit) {
       	      this.merchant = m;
	      this.product = p;
	      this.currentPrice = cp;
	      this.normalPrice = np;
	      this.limitedSupply = limit;
       }

       public Merchant getMerchant() {
       	      return this.merchant;
       }

       public Product getProduct() {
       	      return this.product;
       }

       public double getNormalPrice() {
       	      return this.normalPrice;
       }
       
       public double getCurrentPrice() {
       	      return this.currentPrice;
       }

       public boolean getIsLimitedSupply() {
       	      return this.limitedSupply;
       }
}

q4)
import java.util.ArrayList;
public class Store {
       private ArrayList<Offer> offers;

       public Store() {
       	      this.offers = new ArrayList<Offer>();
       }

       //returns an arraylist of every item which has a cheaper
       //current price than normal price
       public ArrayList<Offer> getAllOnSale() {
       	      ArrayList<Offer> onSaleItems = new ArrayList<Offer>();
	      for (int i=0; i < this.offers.size(); i++) {
	      	  Offer current = this.offers.get(i);
		  if (current.getCurrentPrice() < current.getNormalPrice()) {
		     onSaleItems.add(current);
		  }
	      }

	      return onSaleItems;
       }

       public Offer getMostDollarSavings() {
	      // this problem is a variation on the problem
	      //"find the maximum value of an array"
	      Offer best = null;
	      double savingsOfBest = 0;

	      for (int i=0; i < this.offers.size(); i++) {
	      	  Offer current = this.offers.get(i);
		  double savingsOfCurrent = current.getCurrentPrice() - current.getNormalPrice();
		  if (best == null || savingsOfCurrent < savingsOfBest) {
		     	   best = current;
			   savingsOfBest = savingsOfCurrent;
		  }
	      }

	      return best;
       }


       //this problem is identical to the above except we have
       //a different way to calculate the "best"
       public Offer getMostPercentSavings() {
	      // this problem is a variation on the problem
	      //"find the maximum value of an array"
	      Offer best = null;
	      double savingsOfBest = 0;

	      for (int i=0; i < this.offers.size(); i++) {
	      	  Offer current = this.offers.get(i);
		  //the following few lines are the only changes!
		  double savingsOfCurrent = current.getCurrentPrice() / current.getNormalPrice();
		  //this will now be > instead of < because
		  //we want to see which offer's current price
		  //is the smallest of the original price
		  //You could use a slightly different formula
		  //to take the offer which saved you the most
		  //percent, but it's the same result either way.
		  if (best == null || savingsOfCurrent >  savingsOfBest) {
		     	   best = current;
			   savingsOfBest = savingsOfCurrent;
		  }
	      }

	      return best;
       }

       //this is largely the same as getAllOnSale() except with a different condition
       public ArrayList<Product> getProduct(String name)  {
       	      ArrayList<Product> matchingProducts = new ArrayList<Product>();
	      for (int i=0; i < this.offers.size(); i++) {
	      	  Offer current = this.offers.get(i);
		  if (current.getProduct().getName().equals(name)) {
		     matchingProducts.add(current.getProduct());
		  }
	      }

	      return matchingProducts;
       }

       public ArrayList<Offer> getAllLessThan(double price) {
       	      ArrayList<Offer> lessItems = new ArrayList<Offer>();
	      for (int i=0; i < this.offers.size(); i++) {
	      	  Offer current = this.offers.get(i);
		  if (current.getCurrentPrice() < price) {
		     lessItems.add(current);
		  }
	      }

	      return lessItems;
       }

       public ArrayList<Offer> getAllOffers() {
       	      return new ArrayList<Offer>(this.offers);
       }
}

public class Shopper {
       public static ArrayList<Offer> getAllOffers(ArrayList<Store> stores)  {
       	      ArrayList<Offer> offers = new ArrayList<Offer>();
	      for (int i=0; i < stores.size(); i++) {
	      	  offers.addAll(stores.get(i).getAllOffers());
		  //note that you could use a loop instead of the
		  //above statement if you didn't know of the addAll
		  //method
	      }

	      return offers;
       }

       public static double getValue(ArrayList<Offer> offers) {
       	      if (offers == null) {
	      	 return 0;
	      }

       	      double value = 0;
	      for (int i=0; i < offers.size(); i++) {
	      	  value = value + PracticeLongAnswer.getUtility(offers.get(i).getProduct());
	      }

	      return value;
       }

       /*note that question omitted a step to convert the stores to an arraylist of offers. Sorry!*/
       public static ArrayList<Offer> getMostUseful(ArrayList<Store> stores, double availableMoney) {
       	      return getMostUseful(getAllOffers(stores), availableMoney, new ArrayList<Offer>());
       }

       private static ArrayList<Offer> getMostUseful(ArrayList<Offer> offers, double availableMoney, ArrayList<Offer> chosen) {
       	       if (offers.size() == 0) {
	       	  return chosen;
	       }

	       if (availableMoney < 0) {
	       	  return null;
	       }

	       ArrayList<Offer> duplicateOffers = new ArrayList<Offer>(offers);
	       ArrayList<Offer> duplicateChosen = new ArrayList<Offer>(chosen);
	       Offer first = duplicateOffers.get(0);
	       duplicateOffers.remove(0);
	       duplicateChosen.add(first);
	       ArrayList<Offer> withFirst = getMostUseful(duplicateOffers, availableMoney - first.getCurrentPrice(), duplicateChosen);
	       duplicateOffers = new ArrayList<Offer>(offers);
	       duplicateChosen = new ArrayList<Offer>(chosen);
	       duplicateOffers.remove(0);
	       ArrayList<Offer> withoutFirst = getMostUseful(duplicateOffers, availableMoney, duplicateChosen);

	       if (getValue(withFirst) < getValue(withoutFirst)) {
	       	  return withoutFirst;
	       }
	       else {
	       	    return withFirst;
	       }
       }
}