Write a Java program to demonstrate the use of linked-lists. You will not be usi

Question

Write a Java program to demonstrate the use of linked-lists. You will not be using the LinkedList from java.util. Rather, you will be creating your own OrderedList class and implement a linked list with reference variables. In addition you will implement the Iterable and Iterator interfaces. This exercise is intended to build the tools necessary to understanding complex memory management (although not to the degree the C programming language grants) rather than using an array-backed class like Vector. In addition, your class will have the Iterable capability that will allow you to use your class objects in a for-each loop. The key to this design is that the list will be ordered (sorted ascending) and will not contain duplicates. Your code will maintain this order. Refer to the class notes on the visual construction of a linked list. You will work with three file names provided (in the order below) on the command line: d6.dat d6.delete d6.out [or whatever you call it on the command line] The files d6.dat and d6.delete will be provided for you. You will produce an outputfile that contains all of d6.dat in sorted order, minus the duplicates and minus any items specified in d6.delete. The solution is as follows: Create an OrderedList class that implements the Iterable interface. This will define the inner classes OLIterator and Node. The Node class simply defines instance variables for the data and the reference to the next node in the list in addition to a simple constructor. The OLIterator class will implement the Iterator interface which includes methods for hasNext(), next() and remove(). Your remove() method need not do anything but must be present to satisfy the interface. The final pieces of the OrderedList class are the instance variable for the head of the list, a constructor and the methods: boolean isEmpty(); boolean insert(String item); void delete(String item); Once you have processed the d6.dat file and the d6.delete file, it is a simple matter of iterating over the list and writing the object data to the outputfile. The output file size will be 22,725 or 27,270 bytes depending on platform and methods used.

Explanation / Answer

// Demonstrate LinkedList. import java.util.*; class LinkedListDemo { public static void main(String args[]) { // create a linked list LinkedList ll = new LinkedList(); // add elements to the linked list ll.add("F"); ll.add("B"); ll.add("D"); ll.add("E"); ll.add("C"); ll.addLast("Z"); ll.addFirst("A"); ll.add(1, "A2"); System.out.println("Original contents of ll: " + ll); // remove elements from the linked list ll.remove("F"); ll.remove(2); System.out.println("Contents of ll after deletion: " + ll); // remove first and last elements ll.removeFirst(); ll.removeLast(); System.out.println("ll after deleting first and last: " + ll); // get and set a value Object val = ll.get(2); ll.set(2, (String) val + " Changed"); System.out.println("ll after change: " + ll); } } The output from this program is shown here: Original contents of ll: [A, A2, F, B, D, E, C, Z] Contents of ll after deletion: [A, A2, D, E, C, Z] ll after deleting first and last: [A2, D, E, C] ll after change: [A2, D, E Changed, C]

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.