Question

Using Java coding, complete the following:

This program should implement a LinkedList data structure to handle the management of student records. It will need to be
able to store any number of students, using a Linked List.

LinearNode.java can be used to aid creating this program

Student should be a class defined with the following:
   • String name
   • int year
   • A linked list of college classes (college classes are represented using strings)
   • An ArrayList of grades (these are ints)
   • Getter/Setters for the private data
   • Method to determine average of all grades
   • ToString method to print students name, year, number of courses taken, and grade average as a
   letter

Also add a Main class that performs the following operations:
   • Add four students to the linked list
   • Add five grades to each student such that one student is an A, B, C, and D student (should be in
   descending order)
   • Print the second student using its toString()
   • Print the last student using its toString()
   • Remove the third student from the linked list
   • Print the last student using its toString()
   • Determine the average of all students first grade and print this

LinearNode.java

public class LinearNode<T> {

        private T element;                                      // element
        private LinearNode<T> next;                       // reference to next element
        
        public LinearNode ()                            // POST: empty node
        {       element = null;
                next = null;
        }
        
        public LinearNode (T elem)                      // POST: node set to element
        {       element = elem;
                next = null;    }
        
        // accessors and modifiers
        public LinearNode<T> getNext()
        {       return next;    }
        
        public void setNext (LinearNode<T> node)
        {       next = node;    }
        
        public T getElement ( )
        {       return element; }
        
        public void setElement (T elem)
        {       element = elem; }
}

Answer 1

Student.java

import java.util.ArrayList;

public class Student {
   // instance variables
   private String name;
   private int year;
   private String college;
   // ArrayList to store grades
   private ArrayList<Integer> grades;
   // default constructor
   Student() {
       super();
   }
   // parameterized constructor
   Student(String name, int year, String college, ArrayList<Integer> grades) {
       super();
       this.name = name;
       this.year = year;
       this.college = college;
       this.grades = grades;
   }
   // setter and getter methods
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   public int getYear() {
       return year;
   }
   public void setYear(int year) {
       this.year = year;
   }
   public String getCollege() {
       return college;
   }
   public void setCollege(String college) {
       this.college = college;
   }
   public ArrayList<Integer> getGrades() {
       return grades;
   }
   public void setGrades(ArrayList<Integer> grades) {
       this.grades = grades;
   }
   // method to calculate average of all grades
   public double averageOfAllGrades() {
       double gradesTotal=0;
       for (Integer grade : grades)
           gradesTotal+=grade;
       return gradesTotal/grades.size();
   }
   @Override
   public String toString() {
       return "Student:"
               +"\nName: "+name
               +"\nYear: "+year
               +"\nNumber of courses taken: "+grades.size()
               +"\nGrades average: "+averageOfAllGrades()+"\n";
   }
}

Main.java

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

public class Main {
   public static void main(String[] args) {
       // create a LinkedList of type Student
       List<Student> students=new LinkedList<>();
       // create array list to store grades
       ArrayList<Integer> grades=new ArrayList<>();
       grades.add(85);
       grades.add(91);
       grades.add(78);
       grades.add(83);
       grades.add(85);
       // create student object
       Student student1=new Student("Steve", 2, "FC College",grades);
       grades=new ArrayList<>();
       grades.add(75);
       grades.add(91);
       grades.add(78);
       grades.add(83);
       grades.add(81);
       Student student2=new Student("Rohit", 2, "NJ College",grades);
       grades=new ArrayList<>();
       grades.add(98);
       grades.add(71);
       grades.add(91);
       grades.add(78);
       grades.add(83);
       Student student3=new Student("Tony", 3, "SD College",grades);
       grades=new ArrayList<>();
       grades.add(77);
       grades.add(75);
       grades.add(91);
       grades.add(78);
       grades.add(83);
       Student student4=new Student("John", 1, "PN College",grades);
       // add all four students into linked list
       students.add(student1);
       students.add(student2);
       students.add(student3);
       students.add(student4);
       // print second student from linked list
       // -- get(1) means second position because index starts from 0
       System.out.println("Second student\n"+students.get(1));
       // print last student
       System.out.println("Last student:\n"+students.get(students.size()-1));
       students.remove(2); // remove third student
       // again print last student
       System.out.println("Last student:\n"+students.get(students.size()-1));
       double sum=0;
       // calculate average of all students first grade
       for (Student stud : students) {
           sum+=stud.getGrades().get(0);
       }      
       // print average of all students first grade
       System.out.println("\nAverage of all students first grade: "+sum/students.size());
   }
}

Output