Question

You are to write a Java Class using Generics. This class is to be a Double Linked List container for holding other objects which are comparable. The Class should support the following features: Print the elements of the collection in order (ascending). Insert an item. Remove an item. Empty the collection. Find the index of an element, using a binary recursive search. The program should include a driver class (Main) that provides a command line input/output. This driver class should: Print a prompt indicating options to test each of the features above. Provide an option to exit. Accept command-line input for both integer and decimal values (such as 2.3). Additional Requirements The class should be named MyList.java The main class should be named Main.java You are not to use any third party packages for List type collections. The only packages you should be using are for the Input/Output and for holding the input data. All code should have proper error checking and should have no unexpected termination. If invalid data is input, the user should be informed of it and allowed to re-enter the data.

Answer 1

Menu- 1. print list 2. insert 3. remove 4. empty list 5. find index 6. exit Enter your choice 2 Enter element to insert :1 -- Menu 1. print list 2. insert 3. remove 4. empty list 5. find index 6. exit Enter your choice: 2 Enter element to insert 20 - Menu -- 1. print list 2. insert 3. remove 4. empty list 5. find index 6. exit

Enter your choice: -- し13t content ー- 10 20 -- Menu 1. print list 2. insert 3. remove 4. empty list 5. find index 6. exit Enter your choice: 2 Enter element to insert :30 -- Menu- 1. print list 2. insert 3. remove 4. empty list 5. find index 6. exit Enter your choice -List content -

=========================================

//Node class for doubly linked list structure
class Node<T> {

   public T data;
   public Node<T> next;
   public Node<T> previous;

   // Public constructor
   public Node(T id) {
       data = id;
   }
}

// MyList class for doubly linked list operations
public class MyList<T> {

   private Node<T> first;
   private Node<T> last;

   // Default constructor
   public MyList() {
       first = null;
       last = null;
   }

   private boolean isEmpty() {
       return first == null;
   }

   // 1. print function
   public void print() {

       System.out.println("-- List content --");
       Node<T> temp = first;
      
       if(temp== null) {
           System.out.println("No elements are present to display!");
       } else {
           while (temp != null) {
               System.out.print(temp.data+" ");
               temp = temp.next;
           }
          
           System.out.print("\n");
       }
   }

   // 2. insert function
   public void insert(T data) {

       Node<T> newNode = new Node<T>(data);

       // Check if empty
       if (isEmpty()) {
           first = newNode;
       } else {
           last.next = newNode;
           newNode.previous = last;
       }
       last = newNode;
   }

   // 3. delete function
   public Node<T> delete(T key) {

       Node<T> temp = first;

       // Get the node where the key is present
       while (temp.data != key) {

           temp = temp.next;
           if (temp == null)
               return null;
       }

       // Check for fist node
       if (temp == first) {
           first = temp.next;
       } else {
           temp.previous.next = temp.next;
       }

       // Check for last node
       if (temp == last) {
           last = temp.previous;
       } else {
           temp.next.previous = temp.previous;
       }

       return temp;
   }

   // 4. empty list
   public void emptyList() {

       // by making null for first and last nodes
       first = null;
       last = null;
   }

   // 5. find index
   public int findIndex(T key) {

       int index = -1;
       int i = 0;
       Node<T> temp = first;
       while (temp != null) {
           if (temp.data == key) {
               index = i;
               break;
           }
           i++;
           temp = temp.next;
       }

       return index;
   }

}

=========================================

import java.util.Scanner;

public class Main {

   public static void main(String[] args) {
      
       //Creating scanner object to read input from keyboard
       Scanner sc = new Scanner(System.in);
      
       //Create object of MyList
       MyList<Integer> myList = new MyList<Integer>();
      
       int input;
      
       while(true) {
          
           System.out.println("-- Menu -- ");
           System.out.println("1. print list");
           System.out.println("2. insert");
           System.out.println("3. remove");
           System.out.println("4. empty list");
           System.out.println("5. find index");
           System.out.println("6. exit");

           System.out.println("Enter your choice :");
           int choice = sc.nextInt();
          
           switch(choice) {
          
               case 1:
                   myList.print();
                   break;
                  
               case 2:
                   System.out.print("Enter element to insert :");
                   input = sc.nextInt();
                   myList.insert(input);
                   break;
  
               case 3:
                   System.out.print("Enter element to delete :");
                   input = sc.nextInt();
                   myList.delete(input);
                   break;

               case 4:
                   myList.emptyList();
                   break;

               case 5:
                   System.out.print("Enter element to search :");
                   input = sc.nextInt();
                   System.out.println("index found at position "+myList.findIndex(input));
                   break;
                  
               case 6:
                   break;
                  
               default:
                   System.out.println("Invalid Chioce!");

           }
          
           //If choice is 6 exit while loop
           if(choice==6) {
               break;
           }
          
       }
      
       //Close input stream
       sc.close();

   }
}