Question

For this lab, you will be writing search algorithms. I have provided method signatures for you to follow. The code I am providing already compiles, so as you write more code you can continually test it as you go. Write all of the methods in order as they appear in the code. DO NOT move on to another method until the previous method is fully tested.

1. The CandyBar class defines an object of type CandyBar. This object has three pieces of information: a name, a weight and a wrapper color. Please DO NOT modify this code. Use this class as it is.

2. You will write your new code in Lab16.java. The main() method includes questions you must find the answers to using methods you will write.

3. Write the method definitions one by one for all four methods, testing after each one. DO NOT write a second method before the first one works perfectly. In doing this you must ask yourself the following questions for each:

a. What information does the method provide (input parameters)?

b. What information does the method return?

d. What should the method do?

Lab16.java -

import java.util.ArrayList;

/**
* This lab practices writing and using search algorithms.
*
* @author
* @version 2018
*/
public class Lab16
{
public static void main(String[] args)
{
ArrayList<CandyBar> bars = new ArrayList<CandyBar>();
addCandyBarsToList(bars);
  
/**
* Use the methods you wrote below to answer all of
* the following questions.
*/

/**
* Part A:
*/

/**
* Is Twix in the list?
* If so, print all information about it.
* If not, print a message to the user.
*/
  
/**
* Is Mounds in the list?
* If so, print all information about it.
* If not, print a message to the user.
*/
  
  
/**
* Part B:
*/
  
/**
* Print all the names of candy bars with yellow wrappers.
*/
  

/**
* Part C:
*/

/**
* Count how many candy bars are 1.75 oz or more.
*/
  
  
/**
* Part D:
*/

/**
* Is there a candy bar that is 1.86 oz?
* If so, print the information.
* If not, print a message to the user.
* Write a binary search method to get the answer.
*/
  

}
  
/**
* This method searches a list to find a candy bar by name.
*
* @param   list   the list to search
* @param   n     a name to find
* @return           the index of the candy bar
*/
public static int findCandyBar(ArrayList<CandyBar> list, String n)
{
return -1;
}
  
/**
* This method prints the names of the candy bars that have a certain
* wrapper color.
*
* @param   list   the list to search
* @param   c     the color wrapper to find
*/
public static void findByColor(ArrayList<CandyBar> list, CandyBar.Color c)
{
  
}
  
/**
* This method counts the number of candy bars that weigh greater than
* or equal to the weight input parameter.
*
* @param   list   the list to search
* @param   w     the weight to compare to
* @return           the count of candy bars
*/
public static int countByWeight(ArrayList<CandyBar> list, double weight)
{
return 0;
}
  
/**
* This method searches a list using binary search.
*
* @param   list   the list to search
* @param   first the first index
* @param   last   the last index
* @param   w       the value to search for
* @return           the index of the candy bar
*/
public static int binaryFind(ArrayList<CandyBar> list, int first, int last, double w)
{
return -1;
}
  
/**
* This method adds candy bars to a list.
*
* @param   list   the list to add to
*/
public static void addCandyBarsToList(ArrayList<CandyBar> list)
{
CandyBar kitkat = new CandyBar("KitKat", CandyBar.Color.RED, 1.5);
list.add(kitkat);
CandyBar grand = new CandyBar("One-hundred Grand", CandyBar.Color.RED, 1.5);
list.add(grand);
CandyBar crunch = new CandyBar("Crunch", CandyBar.Color.BLUE, 1.55);
list.add(crunch);
CandyBar hershey = new CandyBar("Hershey", CandyBar.Color.BROWN, 1.55);
list.add(hershey);
CandyBar krackel = new CandyBar("Krackel", CandyBar.Color.RED, 1.55);
list.add(krackel);
CandyBar caramello = new CandyBar("Caramello", CandyBar.Color.PURPLE, 1.6);
list.add(caramello);
CandyBar what = new CandyBar("Whatchamacallit", CandyBar.Color.YELLOW, 1.6);
list.add(what);
CandyBar almond = new CandyBar("Almond Joy", CandyBar.Color.BLUE, 1.61);
list.add(almond);
CandyBar goodbar = new CandyBar("Mr. Goodbar", CandyBar.Color.YELLOW, 1.75);
list.add(goodbar);
CandyBar twix = new CandyBar("Twix", CandyBar.Color.GOLD, 1.79);
list.add(twix);
CandyBar henry = new CandyBar("Oh Henry", CandyBar.Color.YELLOW, 1.8);
list.add(henry);
CandyBar milkyWay = new CandyBar("Milky Way", CandyBar.Color.GREEN, 1.84);
list.add(milkyWay);
CandyBar payDay = new CandyBar("PayDay", CandyBar.Color.ORANGE, 1.85);
list.add(payDay);
CandyBar snickers = new CandyBar("Snickers", CandyBar.Color.BLUE, 1.86);
list.add(snickers);
CandyBar butterfinger = new CandyBar("Butterfinger", CandyBar.Color.YELLOW, 1.9);
list.add(butterfinger);
CandyBar musketeers = new CandyBar("Three Musketeers", CandyBar.Color.SILVER, 1.92);
list.add(musketeers);
CandyBar reeses = new CandyBar("Reese's FastBreak", CandyBar.Color.ORANGE, 2);
list.add(reeses);
CandyBar babyRuth = new CandyBar("Baby Ruth", CandyBar.Color.SILVER, 2.1);
list.add(babyRuth);
}
}

CandyBar.java -

public class CandyBar
{
public enum Color { BLUE, BROWN, GOLD, GREEN, ORANGE, PURPLE, RED, SILVER, WHITE, YELLOW }
  
// instance variables
private String name;
private double weight;
private Color wrapper;

/**
* Constructor for objects of class CandyBar
*/
public CandyBar(String n, Color c, double w)
{
this.name = n;
this.weight = w;
this.wrapper = c;
}

public String getName()
{
return this.name;
}
  
public double getWeight()
{
return this.weight;
}
  
public Color getWrapperColor()
{
return this.wrapper;
}
  
public void printInfo()
{
System.out.println(this.name);
System.out.printf("%.1f oz with a ", this.weight);
System.out.println(this.wrapper + " wrapper");
}
}

Answer 1

Hi,

Please find the java code below:

Please test the code.

////////////////////

package candybar;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

/**
* This lab practices writing and using search algorithms.
*
* @author
* @version 2018
*/
public class Lab16
{
   public static void main(String[] args)
   {
       ArrayList<CandyBar> bars = new ArrayList<CandyBar>();
       addCandyBarsToList(bars);

       /**
       * Use the methods you wrote below to answer all of
       * the following questions.
       */

       /**
       * Part A:
       */

       /**
       * Is Twix in the list?
       * If so, print all information about it.
       * If not, print a message to the user.
       */

       /**
       * Is Mounds in the list?
       * If so, print all information about it.
       * If not, print a message to the user.
       */

       /**
       * Part B:
       */

       /**
       * Print all the names of candy bars with yellow wrappers.
       */

       /**
       * Part C:
       */

       /**
       * Count how many candy bars are 1.75 oz or more.
       */

       /**
       * Part D:
       */

       /**
       * Is there a candy bar that is 1.86 oz?
       * If so, print the information.
       * If not, print a message to the user.
       * Write a binary search method to get the answer.
       */

   }

   /**
   * This method searches a list to find a candy bar by name.
   *
   * @param   list   the list to search
   * @param   n     a name to find
   * @return           the index of the candy bar
   */
   public static int findCandyBar(ArrayList<CandyBar> list, String n)
   {
       for (int i=0; i<= list.size(); i++){
           if (list.get(i).getName().equals(n)){
               return i;
           }         
       }
       return -1;
   }

   /**
   * This method prints the names of the candy bars that have a certain
   * wrapper color.
   *
   * @param   list   the list to search
   * @param   c     the color wrapper to find
   */
   public static void findByColor(ArrayList<CandyBar> list, CandyBar.Color c)
   {
       System.out.println("Candy bars that have " + c + " color are:");  
       for (int i=0; i<= list.size(); i++){
           if (list.get(i).getWrapperColor().equals(c)){
               System.out.println(list.get(i).getName());
           }         
       }
   }

   /**
   * This method counts the number of candy bars that weigh greater than
   * or equal to the weight input parameter.
   *
   * @param   list   the list to search
   * @param   w     the weight to compare to
   * @return           the count of candy bars
   */
   public static int countByWeight(ArrayList<CandyBar> list, double weight)
   {
       int count=0;
       for (int i=0; i<= list.size(); i++){
           if (list.get(i).getWeight() >= weight){
               count++;
           }         
       }
       return count;
   }

   /**
   * This method searches a list using binary search.
   *
   * @param   list   the list to search
   * @param   first the first index
   * @param   last   the last index
   * @param   w       the value to search for
   * @return           the index of the candy bar
   */
   public static int binaryFind(ArrayList<CandyBar> list, int first, int last, double w)
   {
       //Sort the list
       Collections.sort(list, new Comparator<CandyBar>() {
           @Override
           public int compare(CandyBar o1, CandyBar o2) {
               return Double.valueOf(o1.getWeight()).compareTo(Double.valueOf(o2.getWeight()));
           }
       });
       while(last >= first) {
           int mid = (last + first)/2;
           if(list.get(mid).getWeight() == w){
               return mid;
           }
           else if(list.get(mid).getWeight() < w) {
               first = mid + 1;
           }
           else {
               last = mid - 1;
           }
       }
       return -1;
   }

   /**
   * This method adds candy bars to a list.
   *
   * @param   list   the list to add to
   */
   public static void addCandyBarsToList(ArrayList<CandyBar> list)
   {
       CandyBar kitkat = new CandyBar("KitKat", CandyBar.Color.RED, 1.5);
       list.add(kitkat);
       CandyBar grand = new CandyBar("One-hundred Grand", CandyBar.Color.RED, 1.5);
       list.add(grand);
       CandyBar crunch = new CandyBar("Crunch", CandyBar.Color.BLUE, 1.55);
       list.add(crunch);
       CandyBar hershey = new CandyBar("Hershey", CandyBar.Color.BROWN, 1.55);
       list.add(hershey);
       CandyBar krackel = new CandyBar("Krackel", CandyBar.Color.RED, 1.55);
       list.add(krackel);
       CandyBar caramello = new CandyBar("Caramello", CandyBar.Color.PURPLE, 1.6);
       list.add(caramello);
       CandyBar what = new CandyBar("Whatchamacallit", CandyBar.Color.YELLOW, 1.6);
       list.add(what);
       CandyBar almond = new CandyBar("Almond Joy", CandyBar.Color.BLUE, 1.61);
       list.add(almond);
       CandyBar goodbar = new CandyBar("Mr. Goodbar", CandyBar.Color.YELLOW, 1.75);
       list.add(goodbar);
       CandyBar twix = new CandyBar("Twix", CandyBar.Color.GOLD, 1.79);
       list.add(twix);
       CandyBar henry = new CandyBar("Oh Henry", CandyBar.Color.YELLOW, 1.8);
       list.add(henry);
       CandyBar milkyWay = new CandyBar("Milky Way", CandyBar.Color.GREEN, 1.84);
       list.add(milkyWay);
       CandyBar payDay = new CandyBar("PayDay", CandyBar.Color.ORANGE, 1.85);
       list.add(payDay);
       CandyBar snickers = new CandyBar("Snickers", CandyBar.Color.BLUE, 1.86);
       list.add(snickers);
       CandyBar butterfinger = new CandyBar("Butterfinger", CandyBar.Color.YELLOW, 1.9);
       list.add(butterfinger);
       CandyBar musketeers = new CandyBar("Three Musketeers", CandyBar.Color.SILVER, 1.92);
       list.add(musketeers);
       CandyBar reeses = new CandyBar("Reese's FastBreak", CandyBar.Color.ORANGE, 2);
       list.add(reeses);
       CandyBar babyRuth = new CandyBar("Baby Ruth", CandyBar.Color.SILVER, 2.1);
       list.add(babyRuth);
   }
}

////////////////////

Let me know if you need more help on this.

Hope this helps,
Thanks.