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.

Student_ID	Student_Name
00236	Salman
00663	Suliman
00998	Abdulrahman

1. Print the complete list using toString() method.
2. Delete head note from both list.
3. Print the both list using toString() method.

in java

Answer 1

Here is the completed code for this problem. Go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

// StudentLinkedList.java

public class StudentLinkedList {

      //nodes to represent head and tail

      private StudentNode head;

      private StudentNode tail;

      //current size of the list

      private int size;

     

      //constructor initializing empty list

      public StudentLinkedList() {

            head = null;

            tail = null;

            size = 0;

      }

     

      //method to add a student to the head

      public void addHead(String name, String id) {

            //creating a new node with given name and id

            StudentNode node = new StudentNode(name, id);

            //if this is first value, adding as both head and tail

            if (size == 0) {

                  head = node;

                  tail = node;

            } else {

                  //adding before head, and updating head

                  node.next = head;

                  head = node;

            }

            //updating size

            size++;

      }

     

      //method to add a student to the tail

      public void addTail(String name, String id) {

            //creating a new node with given name and id

            StudentNode node = new StudentNode(name, id);

            //if this is first value, adding as both head and tail

            if (size == 0) {

                  head = node;

                  tail = node;

            } else {

                  //adding after tail, updating tail

                  tail.next = node;

                  tail = node;

            }

            size++;

      }

     

      //removes a node from the head, if not empty

      public void deleteHead() {

            //proceeding only if list is not empty

            if (size > 0) {

                  //removing head node

                  head = head.next;

                  //setting tail to null if head become null

                  if (head == null) {

                        tail = null;

                  }

                  //updating size

                  size--;

            }

      }

     

      //returns a String representation of the list

      public String toString() {

            String data = "";

            //appending each node's toString() value to a String and returning it

            for (StudentNode node = head; node != null; node = node.next) {

                  data += node.toString() + " ";

            }

            return data;

      }

     

      //an inner class representing a node in the linked list

      class StudentNode {

            //attributes

            String name;

            String id;

            StudentNode next;

           

            //constructor taking name and id of a student

            public StudentNode(String name, String id) {

                  this.name = name;

                  this.id = id;

                  next = null;

            }

           

            //returns a String containing name and id details

            public String toString() {

                  return "[name: " + name + ", id: " + id + "]";

            }

      }//end of StudentNode class

     

      //main method for testing

      public static void main(String[] args) {

            //creating a list, adding some students using addHead() method

            StudentLinkedList list1 = new StudentLinkedList();

            list1.addHead("Mohammad", "00235");

            list1.addHead("Ahmed", "00662");

            list1.addHead("Ali", "00999");

            list1.addHead("Fahad", "00171");

            //printing the list

            System.out.println(list1);

                 

            //creating a list, adding some students using addTail() method

            StudentLinkedList list2 = new StudentLinkedList();

            list2.addTail("Salman", "00236");

            list2.addTail("Suliman", "00663");

            list2.addTail("Abdulrahman", "00998");

            //printing the list

            System.out.println(list2);

      }

} //end of StudentLinkedList class

/*OUTPUT*/

[name: Fahad, id: 00171] [name: Ali, id: 00999] [name: Ahmed, id: 00662] [name: Mohammad, id: 00235]

[name: Salman, id: 00236] [name: Suliman, id: 00663] [name: Abdulrahman, id: 00998]