Assignment #5 Solution

Objective: The goal of this assignment is to practice linked list of objects.




Background: El Paso Packaging and Supply Co. comes back to you (again) . They are very happy with your linked list based program. They would like to add more linked list functionality in the program.




As you know from Lab Assignment 4, an input file may look like the following one.




20108




4.5 8.45 12.2

8.0 2.5 4.0

1.0 15.0 18.0

3.5 3.5 3.5

6.0 5.0 10.0




The input filename must be input.txt. Each line contains the width, height and length of a box. The dimensions are separated by spaces. In Lab Assignment 4, you created your own linked list; you were not allowed to use any java.util lists for this revised software. The same conditions apply for this new assignment.




Assignment: All the following conditions from the previous assignment are valid in this assignment. You will not make any change to the Box class.




You are allowed to keep only the next variable public. The rest of the status variables of the Box class must be private.



Write no more than two constructors in the Box class.
The Box class must have a public method named getVolume() that will return the volume of the box.



The Box class must have a public method named isCube() that will return true if the box is cubic, false otherwise.



The Box class must NOT contain any main method.



Feel free to write any additional method in the Box class, as you see fit.




In this assignment, you will write two additional java files LinkedList.java and Runner.java. Notice that in the previous assignment you coded all the linked list operations, including iteration of the linked list, in the Runner.java file. In the new assignment, you will write the basic linked list operations in the LinkedList.java file. You will use a LinkedList object in the Runner.java file as your linked list.




The skeleton of LinkedList.java is provided below.




public class LinkedList {







private Box head;

private Box iterator;




LinkedList(){}




/* Add b as the last node of the linked list.*/ void addNode(Box b){

// WRITE YOUR CODE HERE.

}




/* Insert b in position pos. If insertion is successful




return true, otherwise return false. */



boolean insertNode(Box b, int pos){




// WRITE YOUR CODE HERE.

}




/**Print width, height, length, and volume of each of the boxes in




this linked list. */ void printAllBoxes(){

WRITE YOUR CODE HERE.
}




/** Remove the box in position pos. Return true if removal




is successful, otherwise return false.*/ boolean removeNode(int pos){



WRITE YOUR CODE HERE.
}




/** Return the box in position pos. Return null when pos is * invalid.*/

Box getBox(int pos){

// WRITE YOUR CODE HERE.

}




/**Print width, height, length, and volume of each of the boxes in




this linked list in reverse order.*/ void printReverse(){



WRITE YOUR CODE HERE.



}




/**Initiate the iterator variable*/




void initiateIterator(){

// WRITE YOUR CODE HERE.




}




/**




Return the box in the current iterator position. */
Box getNextBox(){

// WRITE YOUR CODE HERE.

}




}

Fill out the methods in the LinkedList class. The functionality of each of the methods is provided as comments in the code-skeleton above. Note that, for LinkedList.java, you must only write inside the given methods of LinkedList. You are not allowed to write anything outside the body of the given methods of LinkedList.




From Runner.java, whenever you need to iterate over the Box objects of the LinkedList object, you will use the method getNextBox. Notice that you will need to call initiateIterator from Runner before you start iterating. This is because getNextBox will use the status variable iterator, which is initiated by method initiateIterator.




You will use Runner.java to read the input file and construct the LinkedList object. The LinkedList object must hold all the box objects. You are not allowed to use the next variable of any Box object directly in Runner.java. That is, the use of anything like temp=temp.next in Runner.java is strictly prohibited.




Runner.java must provide the following functionalities in separate methods.




Read the input text file provided by the client and create a LinkedList object. Show that your printAllBoxes method in the LinkedList class can print all the boxes in the original sequence they were written in the input file. Also demonstrate that the printReverse method in the LinkedList class prints the boxes in reverse order of their appearance in the linked list.
Find the smallest box in the LinkedList object. Report the position, dimensions, and volume of the smallest object. Position of an object in a linked list is equivalent of index in an array. You must call the method getNextBox of the LinkedList object to iterate over the linked list.



Find the largest box in the LinkedList object. Report the position, dimensions, and volume of the largest box. You already know what a position in a linked list means. You must call the method getNextBox of the LinkedList object to iterate over the linked list.



How many cubic boxes are there in the linked list? Notice that this will require iteration.



Demonstrate that your removeNode method of LinkedList object works properly when called from Runner.java.



Demonstrate that your insertNode method of LinkedList object works properly when called from Runner.java.



Note: It is ok to use a one-dimensional array of length three to keep width, length, and height of a box for string-splitting purpose. You cannot use any array of size larger than three. If you use the split method then this array of size three is inevitable.




Deliverables: Submit three Java files (Box.java, LinkedList.java, and Runner.java) via Blackboard. You have to demo your programs within one week

after the due date. Your demo will be based on your last submission in the Blackboard.




Your TA will instruct you with further details.