main.java

import java.util.Scanner;

public class main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        char again;

        do {

            String studentName, studentID, section;
            int numCourses;

            double totalGPA = 0;
            double weightedTotal = 0;
            double totalUnits = 0;

            int passed = 0;
            int failed = 0;

            double highest = 5.0;
            double lowest = 1.0;

            System.out.println("=================================");
            System.out.println("      GRADE CALCULATOR SYSTEM");
            System.out.println("=================================");

            System.out.print("Enter Student Name : ");
            studentName = sc.nextLine();

            System.out.print("Enter Student ID   : ");
            studentID = sc.nextLine();

            System.out.print("Enter Section      : ");
            section = sc.nextLine();

            while (true) {
                try {

                    System.out.print("Enter Number of Courses: ");
                    numCourses = Integer.parseInt(sc.nextLine());

                    if (numCourses > 0) {
                        break;
                    }

                    System.out.println("Invalid number of courses.");

                } catch (Exception e) {

                    System.out.println("Invalid input.");
                }
            }

            String[] subjects = new String[numCourses];
            double[] gpaGrades = new double[numCourses];
            double[] units = new double[numCourses];
            String[] remarks = new String[numCourses];

            for (int i = 0; i < numCourses; i++) {

                System.out.println("\nCourse " + (i + 1));

                System.out.print("Enter Course Code : ");
                subjects[i] = sc.nextLine();

                while (true) {
                    try {

                        System.out.print("Enter Grade (1.0 - 5.0): ");
                        gpaGrades[i] =
                                Double.parseDouble(sc.nextLine());

                        if (gpaGrades[i] >= 1.0
                                && gpaGrades[i] <= 5.0) {
                            break;
                        }

                        System.out.println(
                                "GPA must be between 1.0 and 5.0.");

                    } catch (Exception e) {

                        System.out.println("Invalid input.");
                    }
                }

                while (true) {
                    try {

                        System.out.print("Enter Units       : ");
                        units[i] =
                                Double.parseDouble(sc.nextLine());

                        if (units[i] > 0) {
                            break;
                        }

                        System.out.println(
                                "Units must be greater than 0.");

                    } catch (Exception e) {

                        System.out.println("Invalid input.");
                    }
                }

                totalGPA += gpaGrades[i];

                weightedTotal += gpaGrades[i] * units[i];
                totalUnits += units[i];

                if (gpaGrades[i] < highest) {
                    highest = gpaGrades[i];
                }

                if (gpaGrades[i] > lowest) {
                    lowest = gpaGrades[i];
                }

                if (gpaGrades[i] <= 3.0) {
                    remarks[i] = "Passed";
                    passed++;
                } else {
                    remarks[i] = "Failed";
                    failed++;
                }
            }

            double averageGPA = totalGPA / numCourses;
            averageGPA =
                    Math.round(averageGPA * 100.0) / 100.0;

            double weightedAverage =
                    weightedTotal / totalUnits;

            weightedAverage =
                    Math.round(weightedAverage * 100.0) / 100.0;

            String overallRemarks;

            if (weightedAverage <= 1.25) {
                overallRemarks = "Summa Cum Laude";
            } else if (weightedAverage <= 1.50) {
                overallRemarks = "Magna Cum Laude";
            } else if (weightedAverage <= 1.75) {
                overallRemarks = "Cum Laude";
            } else if (weightedAverage <= 3.0) {
                overallRemarks = "Passed";
            } else {
                overallRemarks = "Failed";
            }

            System.out.println("\n=================================");
            System.out.println("           GRADE REPORT");
            System.out.println("=================================");

            System.out.println("Student Name : " + studentName);
            System.out.println("Student ID   : " + studentID);
            System.out.println("Section      : " + section);

            System.out.println(
                    "\n---------------------------------------------------");

            System.out.printf(
                    "%-15s %-10s %-10s %-10s%n",
                    "Course",
                    "GPA",
                    "Units",
                    "Remarks");

            System.out.println(
                    "---------------------------------------------------");

            for (int i = 0; i < numCourses; i++) {

                System.out.printf(
                        "%-15s %-10.2f %-10.2f %-10s%n",
                        subjects[i],
                        gpaGrades[i],
                        units[i],
                        remarks[i]);
            }

            System.out.println(
                    "---------------------------------------------------");

            System.out.println("\nAverage GPA        : "
                    + averageGPA);

            System.out.println("Weighted Average   : "
                    + weightedAverage);

            System.out.println("Highest GPA        : "
                    + highest);

            System.out.println("Lowest GPA         : "
                    + lowest);

            System.out.println("Passed Subjects    : "
                    + passed);

            System.out.println("Failed Subjects    : "
                    + failed);

            System.out.println("Overall Remarks    : "
                    + overallRemarks);

            System.out.print(
                    "\nDo you want to compute again? (Y/N): ");

            again = sc.nextLine().toUpperCase().charAt(0);

            System.out.println();

        } while (again == 'Y');

        System.out.println(
                "Thank you for using the system.");

        sc.close();
    }
}