Question

CSBP 319 Data structures - Linked Lists - USE JAVA (NetBeans)

A company would like to implement its inventory of computing machines as a linked list, called ComputerList.

1. Write a Computer node class, called ComputerNode, to hold the following information about a Computer:

• code (as a String) • brand (as a String) • model (as a String) • price (as double) • quantity (as int)

ComputerNode should have constructors and methods (getters, setters, and toString()) to manage the above information as well as the link to next node in the list.

2. Write the ComputerList class to hold objects of the class ComputerNode. This class should define:

• Two instance variables head and size. (size should be updated during insertions and removals from the list)

The constructor of the class is: public ComputerList(){ head = null; size = 0; }

• The ComputerList class should implement the following interface:

public interface CList { public boolean isEmpty(); // returns true if the list is empty, false otherwise

public int listSize(); // returns the number of items in the list     

public ComputerNode getAt(int index); //returns the ComputerNode object at the specified index or null if the list is empty

public void addFirst(ComputerNode item); // adds a Computer at the front of the list

public void addLast(ComputerNode item); // adds a Computer at the end of the list

public void addAt(int index, ComputerNode item); // adds a Computer to the list at the given index

public ComputerNode search(String code); // search and return the Computer with the given code

public ComputerNode[] searchPriceGreaterThan(int p); //search and return an array of the set of ComputerNode items //having a price greater than p

public String removeAt(int index); // removes the Computer from the list that has the given index

public String remove(ComputerNode item); // removes the first item in the list whose data equals // the given item data

public void removeDuplicates(); // removes the duplicates of every Computer in the list (nodes with the same data)

@Override

public String toString(); // implement a toString() method that prints the list in the // format: //[ size: the_size_of_the_list // Computer1, // Computer2, //.... ] }

3.Write a TestComputerList class to test the class ComputerList. This class should have a main method in which you perform the following actions:

• Create a ComputerList object,

• Insert 10 ComputerNode objects into the created Computer List,

• Print the content of your Computer list,

• Find out in the list the items that have a price greater than 3000. Print them out.

• Remove the first element of the list

• Remove the item at index 3

• Print again the content of your Computer list,

• Insert some duplicate Computers in the list

• Print again the content of your Computer list,

• Remove duplicates

• Print again the content of your Computer list,

For each operation above, print a small message that describes the operation you are doing. For example: System.out.println(“Insertion of 10 Computers in the list”);

Answer 1

ANSWER:-

CODE:-

import java.util.*;
interface CList{
   public boolean isEmpty();  
}
class ComputerNode{
   String code, brand, model;
   double price;
   int quantity;
   ComputerNode next;
   ComputerNode(String code, String brand, String model, double price, int quantity){
       this.code = code;
       this.brand = brand;
       this.model = model;
       this.price = price;
       this.quantity = quantity;
       this.next = null;
   }
   ComputerNode(){
       this.code = "";
       this.brand = "";
       this.model = "";
       this.price = 0.0;
       this.quantity = 0;
       this.next = null;
   }
   void setCode(String code){
       this.code = code;
   }
   void setBrand(String brand){
       this.brand = brand;
   }
   void setModel(String model){
       this.model = model;
   }
   void setPrice(double price){
       this.price = price;
   }
   void setQuantity(int quantity){
       this.quantity = quantity;
   }
   void setnext(ComputerNode next){
       this.next = next;
   }
   String getCode(){
       return this.code;
   }
   String getBrand(){
       return this.brand;
   }
   String getModel(){
       return this.model;
   }
   double getPrice(){
       return this.price;
   }
   int getQuantity(){
       return this.quantity;
   }
   public String toString(){
       return "Code: "+this.getCode()+"\n"
       + "Brand: "+this.getBrand()+"\n"
       + "Model: "+this.getModel()+" \n"
       + "Price: "+this.getPrice()+"\n"
       + "Quantity: "+this.getQuantity()+"\n";
   }
}
class ComputerList{
   ComputerNode head;
   int size;
   ComputerList(){
       this.head = null;
       this.size = 0;
   }
   public boolean isEmpty(){
       return head == null;
   }
   public int listSize(){
       return this.size;
   }
   public ComputerNode getAt(int index){
       if(head == null) return null;
       ComputerNode it = head;
       int i=0;
       while(it!=null){
           if(i == index){
               return it;
           }
           i++;
           it = it.next;
       }
       return null;
   }
   public void addFirst(ComputerNode item){
       item.next = head;
       head = item;
       this.size++;
   }
   public void addLast(ComputerNode item){
       ComputerNode it = head;
       if(head == null){
           head = item;
       }else{
           while(it.next!=null){
               it = it.next;
           }
           it.next = item;
       }
       this.size++;
   }
   public void addAt(int index, ComputerNode item){
       if(index==0){
           this.addFirst(item);
       }else if(index == this.size){
           this.addLast(item);
       }else{
           if(head == null){
               return ;
           }else{
               ComputerNode it = head;
               ComputerNode prev = head;
               int i=0;
               while(it!=null){
                   if(i == index){
                       prev.next = item;
                       item.next = it;
                       break;
                   }
                   i++;
                   prev = it;
                   it = it.next;
               }
           }
           this.size++;

       }
   }
   public ComputerNode search(String code){
       ComputerNode it = head;
       while(it!=null){
           if(code.equals(it.getCode())){
               return it;
           }
           it = it.next;
       }
       return null;
   }
   public ComputerNode[] searchPriceGreaterThan(int p){
       ArrayList<ComputerNode> list = new ArrayList<ComputerNode>();
       ComputerNode it = head;
       while(it!=null){
           if(it.getPrice() > p){
               list.add(it);
           }
           it = it.next;
       }
       ComputerNode[] com = new ComputerNode[list.size()];
       for(int i=0;i<list.size();i++){
           com[i] = list.get(i);
       }
       return com;
   }
   public String removeAt(int index){
       if (head == null) return null;
       String removed = null;
       if(index == 0){
           removed = head.toString();
           head = head.next;
       }else{
           ComputerNode it = head;
           ComputerNode prev = head;
           int i=0;
           while(it!=null){
               if(i == index){
                   removed = it.toString();
                   prev.next = it.next;
                   break;
               }
               i++;
               prev = it;
               it = it.next;
           }
       }
       this.size--;
       return removed;
   }
   public String remove(ComputerNode item){
       if (head == null) return null;
       String code = item.getCode();
       String brand = item.getBrand();
       String model = item.getModel();
       double price = item.getPrice();
       int quantity = item.getQuantity();
       String removed = null;
       if(head.getCode() == code && head.getBrand()==brand && head.getModel() == model && head.getPrice() == price && head.getQuantity() == quantity){
           removed = head.toString();
           head = head.next;
       }else{
           ComputerNode it = head;
           ComputerNode prev = head;
           while(it!=null){
               if(it.getCode() == code && it.getBrand()==brand && it.getModel() == model && it.getPrice() == price && it.getQuantity() == quantity){
                   removed = head.toString();
                   prev.next = head.next;
                   break;
               }
               prev = it;
               it = it.next;
           }
       }
       this.size--;
       return removed;
   }
   public boolean contains(ArrayList<ComputerNode> list, ComputerNode item){
       String code = item.getCode();
       String brand = item.getBrand();
       String model = item.getModel();
       double price = item.getPrice();
       int quantity = item.getQuantity();
       for (int i=0;i<list.size() ; i++) {
           ComputerNode it = list.get(i);
           if(it.getCode() == code && it.getBrand()==brand && it.getModel() == model && it.getPrice() == price && it.getQuantity() == quantity){
               return true;
           }
       }
       return false;
   }
   public void removeDuplicates(){
       ArrayList<ComputerNode> list = new ArrayList<ComputerNode>();
       ComputerNode it = head;
       while(it!=null){
           if(!this.contains(list,it)){
               list.add(it);
           }
           it = it.next;
       }
       this.head = null;
       for(int i=0;i<list.size();i++){
           ComputerNode com = list.get(i);
           com.next = null;
           this.addLast(list.get(i));
       }
       this.size = list.size();
   }
   public String toString(){
       String str = "Size: "+this.size+"\n\n";
       ComputerNode it = head;
       while (it!=null) {
           str += it.toString()+"\n";
           it = it.next;
       }
       return str;
   }
}
public class TestComputerList{
   public static void main(String[] args) {
       ComputerList computers = new ComputerList();
       System.out.println("Insertion of 10 Computes in the list:");
       computers.addLast(new ComputerNode("C1","Lenovo","L321",2000,1));
       computers.addLast(new ComputerNode("C2","Lenovo","L432",900,2));
       computers.addFirst(new ComputerNode("C3","ASUS","SUS2.3",5000,1));
       computers.addFirst(new ComputerNode("C4","ASUS","S2.0",899,3));
       computers.addLast(new ComputerNode("C5","HP","H234",2000,1));
       computers.addLast(new ComputerNode("C6","HP","H897",35000,1));
       computers.addAt(4,new ComputerNode("C7","Lenovo","L865",2999,1));
       computers.addAt(7,new ComputerNode("C8","Apple","L321",85000,4));
       computers.addAt(0,new ComputerNode("C9","Apple","L321",95000,3));
       computers.addLast(new ComputerNode("C10","Apple","L321",199999,2));
       System.out.println("Computers in the list:");
       System.out.println(computers);
       ComputerNode[] computersGreater = computers.searchPriceGreaterThan(3000);
       System.out.println("Computers whose price is greater than 3000:");
       for(int i=0;i<computersGreater.length;i++){
           System.out.println(computersGreater[i].toString());
       }
       computers.removeAt(0);
       computers.removeAt(3);
       System.out.println("List after removing first and 3rd indices:");
       System.out.println(computers);
       computers.addFirst(new ComputerNode("C5","HP","H234",2000,1));
       computers.addFirst(new ComputerNode("C6","HP","H897",35000,1));
       System.out.println("List after inserting duplicates:");
       System.out.println(computers);
       computers.removeDuplicates();
       System.out.println("List after removing duplicates:");
       System.out.println(computers);
   }
}

NOTE:- If you need any modifications in the code,please comment below.Please give positive rating.THUMBS UP.

            THANK YOU!!!!

OUTPUT:-