Appendix B — Full Source Code

This appendix includes the complete Java implementation used in the
CS210 Project — Linked List Implementation and Runtime Analysis.

All files were developed in Visual Studio Code (VS Code)
and compiled using Java 17.

Each file plays a defined role within the system’s modular architecture.

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1. Core Data Structures

Node.java — Linked List Node Structure

public class Node {
    Registration studData;
    Node next;

    public Node(Registration studData) {
        this.studData = studData;
        this.next = null;
    }
}

Registration.java — Data Model

public class Registration {
    private String studentID;
    private String courseID;
    private int academicLevel;
    private int studTime;
    private double studDemandScore;

    public Registration(String studentID, String courseID, int academicLevel, int studTime, double studDemandScore) {
        this.studentID = studentID;
        this.courseID = courseID;
        this.academicLevel = academicLevel;
        this.studTime = studTime;
        this.studDemandScore = 0;
    }

    public String getStudentID() { return studentID; }
    public String getCourseID() { return courseID; }
    public int getAcademicLevel() { return academicLevel; }
    public int getStudTime() { return studTime; }
    public double getStudDemandScore() { return studDemandScore; }

    public void setStudDemandScore(double studDemandScore) {
        this.studDemandScore = studDemandScore;
    }

    @Override
    public String toString() {
        return studentID + ";" + courseID + ";" + academicLevel + ";" + studTime + ";" + Math.round(studDemandScore) + ";";
    }
}

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2. Linked List Implementation

LinkedList.java — Custom Implementation

public class LinkedList {
    Node head;
    Node tail;
    int size;

    public void insertNodeAtTail(Registration data) {
        Node newNode = new Node(data);
        if (head == null) {
            head = tail = newNode;
        } else {
            tail.next = newNode;
            tail = newNode;
        }
        size++;
    }

    public Registration[] convToArray() {
        Registration[] array = new Registration[size];
        Node temp = head;
        int i = 0;
        while (temp != null) {
            array[i++] = temp.studData;
            temp = temp.next;
        }
        return array;
    }
}

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3. Supporting Classes

FileService.java — File Handling Layer

import java.io.*;

public class FileService {
    public static LinkedList readRegistrationsFromFile(String filename) {
        return InputValidator.readAndValidateFile(filename);
    }
}

InputValidator.java — Input Processing

import java.io.*;

public class InputValidator {
    public static LinkedList readAndValidateFile(String filename) {
        LinkedList list = new LinkedList();
        try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
            String line;
            while ((line = br.readLine()) != null) {
                String[] parts = line.split(";");
                if (parts.length == 4) {
                    list.insertNodeAtTail(
                        new Registration(
                            parts[0],
                            parts[1],
                            Integer.parseInt(parts[2]),
                            Integer.parseInt(parts[3]),
                            0
                        )
                    );
                }
            }
        } catch (IOException e) {
            System.out.println("Error reading file: " + e.getMessage());
        }
        return list;
    }
}

DemandScorer.java — Demand Calculation Logic

public class DemandScorer {
    public static void calculateScores(LinkedList list) {
        Node current = list.head;
        while (current != null) {
            Registration reg = current.studData;
            double score = 50;

            switch (reg.getAcademicLevel()) {
                case 1 -> score *= 0.75;
                case 2 -> score *= 0.90;
                case 3 -> score *= 1.10;
                case 4 -> score *= 1.25;
                case 5 -> score *= 1.50;
            }

            int t = reg.getStudTime();
            if (t >= 6 && t < 8) score += 5;
            else if (t >= 8 && t < 10) score += 10;
            else if (t >= 14 && t < 16) score -= 5;
            else if (t >= 16 && t < 20) score -= 10;
            else if (t >= 20) score -= 15;

            if (reg.getCourseID().endsWith("1") ||
                reg.getCourseID().endsWith("3") ||
                reg.getCourseID().endsWith("5"))
                score += 20;
            else
                score -= 10;

            reg.setStudDemandScore(score);
            current = current.next;
        }
    }
}