task4.cpp

#include <iostream>
#include <cmath>
#include <iomanip>

using namespace std;

// Display menu
void showMenu() {
    cout << "\n========================================\n";
    cout << "          SCIENTIFIC CALCULATOR\n";
    cout << "========================================\n";
    cout << "1. Addition\n";
    cout << "2. Subtraction\n";
    cout << "3. Multiplication\n";
    cout << "4. Division\n";
    cout << "5. Power (x^y)\n";
    cout << "6. Square Root\n";
    cout << "7. Sine\n";
    cout << "8. Cosine\n";
    cout << "9. Tangent\n";
    cout << "10. Logarithm (base 10)\n";
    cout << "11. Natural Logarithm (ln)\n";
    cout << "12. Factorial\n";
    cout << "13. Absolute Value\n";
    cout << "14. Exit\n";
    cout << "========================================\n";
}

// Factorial function
unsigned long long factorial(int n) {
    unsigned long long result = 1;

    for (int i = 1; i <= n; i++) {
        result *= i;
    }

    return result;
}

// Convert degree to radians
double toRadians(double degree) {
    return degree * acos(-1.0) / 180.0;
}

int main() {

    int choice;
    double a, b;

    cout << fixed << setprecision(4);

    do {

        showMenu();

        cout << "Enter your choice: ";
        cin >> choice;

        switch (choice) {

            case 1:
                cout << "Enter two numbers: ";
                cin >> a >> b;

                cout << "Result = " << a + b << endl;
                break;

            case 2:
                cout << "Enter two numbers: ";
                cin >> a >> b;

                cout << "Result = " << a - b << endl;
                break;

            case 3:
                cout << "Enter two numbers: ";
                cin >> a >> b;

                cout << "Result = " << a * b << endl;
                break;

            case 4:
                cout << "Enter two numbers: ";
                cin >> a >> b;

                if (b == 0) {
                    cout << "Error: Division by zero is not allowed.\n";
                } else {
                    cout << "Result = " << a / b << endl;
                }

                break;

            case 5:
                cout << "Enter base and exponent: ";
                cin >> a >> b;

                cout << "Result = " << pow(a, b) << endl;
                break;

            case 6:
                cout << "Enter a number: ";
                cin >> a;

                if (a < 0) {
                    cout << "Error: Square root of a negative number is not supported.\n";
                } else {
                    cout << "Result = " << sqrt(a) << endl;
                }

                break;

            case 7:
                cout << "Enter angle in degrees: ";
                cin >> a;

                cout << "sin(" << a << ") = "
                     << sin(toRadians(a)) << endl;
                break;

            case 8:
                cout << "Enter angle in degrees: ";
                cin >> a;

                cout << "cos(" << a << ") = "
                     << cos(toRadians(a)) << endl;
                break;

            case 9:
                cout << "Enter angle in degrees: ";
                cin >> a;

                cout << "tan(" << a << ") = "
                     << tan(toRadians(a)) << endl;
                break;

            case 10:
                cout << "Enter a positive number: ";
                cin >> a;

                if (a <= 0) {
                    cout << "Error: Logarithm is defined only for positive numbers.\n";
                } else {
                    cout << "log10(" << a << ") = "
                         << log10(a) << endl;
                }

                break;

            case 11:
                cout << "Enter a positive number: ";
                cin >> a;

                if (a <= 0) {
                    cout << "Error: Natural logarithm is defined only for positive numbers.\n";
                } else {
                    cout << "ln(" << a << ") = "
                         << log(a) << endl;
                }

                break;

            case 12: {
                int n;

                cout << "Enter a non-negative integer: ";
                cin >> n;

                if (n < 0) {
                    cout << "Error: Factorial is not defined for negative numbers.\n";
                } else if (n > 20) {
                    cout << "Error: Please enter a number up to 20.\n";
                } else {
                    cout << n << "! = " << factorial(n) << endl;
                }

                break;
            }

            case 13:
                cout << "Enter a number: ";
                cin >> a;

                cout << "|" << a << "| = " << fabs(a) << endl;
                break;

            case 14:
                cout << "\nThank you for using Scientific Calculator!\n";
                break;

            default:
                cout << "\nInvalid choice! Please try again.\n";
        }

    } while (choice != 14);

    return 0;
}