Question

Create a program that implements a singly linked list of Students.

Each node must contain the following variables:

• Student_Name
• Student_ID

In main():

1. Create the following list using addHead(). The list must be in the order shown below.

Student_ID	Student_Name
00235	Mohammad
00662	Ahmed
00999	Ali
00171	Fahad

2. Print the complete list using toString() method.
3. Create another list using AddTail(). The list must be in the order shown below.
4. Print the complete list using toString() method.
5. Delete head note from both list.
6. Print the both list using toString() method.

Student_ID	Student_Name
00236	Salman
00663	Suliman
00998	Abdulrahman

7. Add following methods in the previous lab program
   • DeleteTail()
   • DeleteAll()
   • Duplicate()
   • AddAfter()
   • Length()
   • Find()
   • Reverse()

8. Demonstrate all the above methods by calling in them in main.

Answer 1

import java.util.*;
class Students implements Cloneable{
   private String student_ID;
   private String student_Name;
   private Students next;
   int length;
  
  
   public Students(String student_ID, String student_Name){
       this.student_ID = student_ID;
       this.student_Name = student_Name;
       this.next = null;
       length = 0;
   }
  
   public String getStudent_ID(){
       return student_ID;
   }
   public String getStudent_Name(){
       return student_Name;
   }
   public Students getNext(){
       return next;
   }
   public int getLength(){
       return length;
   }
  
  
   public void setStudent_ID(String student_ID){
       this.student_ID=student_ID;
   }
   public void setStudent_Name(String student_Name){
       this.student_Name = student_Name;
   }
   public void setNext(Students next){
       this.next = next;
   }
   public void setLength(int length){
       this.length = length;
   }
  
   public Object clone() throws CloneNotSupportedException
{
return super.clone();
}
  
   public String toString(){
       return "Student Id : "+student_ID+", Student Name : "+student_Name+", next-> "+next;
   }
}

public class Test{
  
  
   public static void main(String[] args) throws Exception{
       Students head = addHead();
       Students tail = addTail();
       System.out.println("haed list =>"+head);
       System.out.println("\ntail list =>"+tail);
       deleteTail(tail);
       Students dupicateList = duplicate(head);
       System.out.println("\nduplicate list =>"+tail);
       Students s = new Students("00001","SN");
       addAfter(head, s);
       System.out.println("haed list =>"+head);
       System.out.println("haed list length =>"+length(head));
       Students s1 = find(head,"00001");
       System.out.println("found student name =>"+s1.getStudent_Name());
      
       Students[] sArr=new Students[2];
       sArr[0] = head;
       sArr[1] = tail;
       deleteAll(sArr);
       System.out.println("haed list =>"+head);
       System.out.println("\ntail list =>"+tail);
      
   }
   public static Students addHead(){
       int length = 1;
       Students students1 = new Students("00235","Mohammad");
       Students students2 = new Students("00662","Ahmed");
       Students students3 = new Students("00999","Ali");
       Students students4 = new Students("00171","Fahad");
       students1.setNext(students2);length++;
       students2.setNext(students3);length++;
       students3.setNext(students4);length++;
       students1.setLength(length);
       return students1;
      
   }
  
   public static Students addTail(){
       int length = 1;
       Students students1 = new Students("00236","Salman");
       Students students2 = new Students("00663","Suliman");
       Students students3 = new Students("00998","Abdulrahman");
       students1.setNext(students2);length++;
       students2.setNext(students3);length++;
       students1.setLength(length);
       return students1;
   }
  
   public static void deleteTail(Students list){
       list = null;
   }
  
   public static void deleteAll(Students[] listArr){
      
       for(int i=0; i<listArr.length; i++){
           listArr[i]= null;
       }
      
   }
  
   public static Students duplicate(Students list) throws CloneNotSupportedException {
       Students dupicateList = (Students)list.clone();
       return dupicateList;
   }
  
   public static void addAfter(Students list, Students s){
       int length = list.getLength();
       Students last = null;
       for(int i=0; i<length; i++){
           last = list.getNext();
       }
       last.setNext(s);
       length++;
       list.setLength(length);
   }
  
   public static int length(Students list){
       return list.getLength();
   }
  
   public static Students find(Students list, String student_ID){
       int length = list.getLength();
       Students s = null;
       Students temp = list;
       if(list.getStudent_ID().equals(student_ID) ){
           return list;
       }
       for(int i=1; i<length; i++){
           s = temp.getNext();
           temp = s;
           //System.out.println(s.getStudent_ID());
           if(s.getStudent_ID().equals(student_ID) ){
               return s;
           }
       }
       return s;
   }

  
  
}