GPA/CGPA Calculator C++, C++ program to calculate CGPA and GPA

#include <iostream>
#include <vector>
#include <limits>
#include <iomanip>
#include <sstream>

using namespace std;

// Function Prototypes
void clearScreen();
void printHeader(const string& title);
void calculateGPA();
void calculateCGPA();
void displayMethod();
void exitApplication();
float inputValidation(const string& prompt);

int main() {
    while (true) {
        clearScreen();
        printHeader("GPA & CGPA Calculator");

        cout << "1. Calculate GPA\n";
        cout << "2. Calculate CGPA\n";
        cout << "3. How GPA & CGPA are calculated\n";
        cout << "4. Exit\n";
        cout << "\nEnter your choice: ";
        int choice = static_cast<int>(inputValidation(""));

        switch (choice) {
        case 1:
            calculateGPA();
            break;
        case 2:
            calculateCGPA();
            break;
        case 3:
            displayMethod();
            break;
        case 4:
            exitApplication();
            return 0;
        default:
            cout << "Invalid choice. Please enter a valid option.\n";
            break;
        }
        cout << "\nPress Enter to continue...";
        cin.ignore(numeric_limits<streamsize>::max(), '\n');
        cin.get(); // Wait for user to press enter
    }
}

void clearScreen() {
    // Clear the screen and move cursor to top-left corner
    cout << "\033[2J\033[1;1H";
}

void printHeader(const string& title) {
    cout << setw(50) << setfill('-') << "\n";
    cout << setw((50 + title.length()) / 2) << setfill(' ') << title << "\n";
    cout << setw(50) << setfill('-') << "\n\n";
}

void calculateGPA() {
    clearScreen();
    printHeader("GPA Calculation");

    int numSubjects = static_cast<int>(inputValidation("Enter the number of subjects: "));
    vector<float> credits(numSubjects), grades(numSubjects);
    float totalCredits = 0, weightedSum = 0;

    for (int i = 0; i < numSubjects; ++i) {
        stringstream ss;
        ss << "Enter credit hours for subject " << i + 1 << ": ";
        credits[i] = inputValidation(ss.str());

        ss.str(""); // Clear the stringstream
        ss.clear(); // Clear any flags
        ss << "Enter grade (point) for subject " << i + 1 << ": ";
        grades[i] = inputValidation(ss.str());

        weightedSum += credits[i] * grades[i];
        totalCredits += credits[i];
    }

    cout << "Your GPA is: " << setprecision(2) << fixed << weightedSum / totalCredits << endl;
}

void calculateCGPA() {
    clearScreen();
    printHeader("CGPA Calculation");

    int numSemesters = static_cast<int>(inputValidation("Enter the number of semesters: "));
    float sumGPA = 0;

    for (int i = 0; i < numSemesters; ++i) {
        stringstream ss;
        ss << "Enter GPA for semester " << i + 1 << ": ";
        sumGPA += inputValidation(ss.str());
    }

    cout << "Your CGPA is: " << setprecision(2) << fixed << sumGPA / numSemesters << endl;
}

void displayMethod() {
    clearScreen();
    printHeader("Calculation Method");
    cout << "GPA is calculated as the sum of (credit hours * grade points) for all subjects, divided by the total credit hours.\n";
    cout << "CGPA is the average of GPA calculated across all semesters.\n\n";
}

void exitApplication() {
    clearScreen();
    cout << "Thank you for using the GPA & CGPA Calculator. Goodbye!\n";
}

float inputValidation(const string& prompt) {
    float input;
    if (!prompt.empty()) cout << prompt;
    while (!(cin >> input) || input < 0) {
        cout << "Invalid input. Please enter a positive number: ";
        cin.clear(); // Clear input buffer
        cin.ignore(numeric_limits<streamsize>::max(), '\n'); // Discard input
    }
    cin.ignore(numeric_limits<streamsize>::max(), '\n'); // Clear the rest of the line
    return input;
}