#include #include #include #include #include #include // For numeric_limits used in input buffer clearing using namespace std;

/*

• This program offers a menu based interface to perform four different types of operations:
• 1. Cosine Functions: Compute cosine, arccosine, or hyperbolic cosine of a given radian value.
• 2. Logarithmic Functions: Calculate common logarithm (base 10) or natural logarithm (base e) of a positive number.
• 3. Decimal/Hexadecimal Conversion: Convert numbers between decimal and hexadecimal, allowing lowercase or uppercase hex output.
• 4. CString Date Format: Reformat dates from mm/dd/yyyy to mm-dd-yyyy format using C-style strings.
• To use, select an option by entering the number (1-4), then follow the prompts to input your data.
• After completing an operation, you can choose to perform another or exit the program. */

int main() { int choice; bool continueProgram = true;

while (continueProgram) {
    cout << "\nSelect an option:\n";
    cout << "1. Cosine Functions\n";
    cout << "2. Logarithmic Functions\n";
    cout << "3. Decimal/Hexadecimal Conversion\n";
    cout << "4. CString Date Format\n";
    cout << "Enter your choice (1-4): ";
    cin >> choice;
    // Clear input buffer after reading an integer to avoid leftover '\n' affecting subsequent getline calls
    cin.ignore(numeric_limits<streamsize>::max(), '\n');

    // Set all floating-point output to fixed-point notation with 3 decimal places
    cout << fixed << setprecision(3);

    if (choice == 1) {
        string cosType;
        double value;
        // Use getline to read full line, supporting inputs like "arccos"
        cout << "Choose type: cos, arccos, or hcos: ";
        getline(cin, cosType);

        cout << "Enter a number in radians: ";
        cin >> value;
        // Clear buffer after numeric input to prevent input issues later
        cin.ignore(numeric_limits<streamsize>::max(), '\n');

        // Compute and print based on user choice using cmath functions
        if (cosType == "cos")
            cout << "Cosine: " << cos(value) << endl;
        else if (cosType == "arccos")
            cout << "Arc Cosine: " << acos(value) << endl;
        else if (cosType == "hcos")
            cout << "Hyperbolic Cosine: " << cosh(value) << endl;
        else
            cout << "Invalid cosine type.\n";
    }

    else if (choice == 2) {
        string logType;
        double value;
        cout << "Choose log type: common log or natural log: ";
        // Using getline to support inputs with spaces like "common log"
        getline(cin, logType);

        cout << "Enter a positive number: ";
        cin >> value;
        cin.ignore(numeric_limits<streamsize>::max(), '\n');

        // showpos forces the '+' sign for positive numbers (optional display detail)
        cout << showpos;

        if (logType == "common log")
            cout << "Common Logarithm: " << log10(value) << endl;  // log base 10
        else if (logType == "natural log")
            cout << "Natural Logarithm: " << log(value) << endl;  // natural log base e
        else
            cout << "Invalid log type.\n";

        // Reset showpos to default (no '+' sign)
        cout << noshowpos;
    }

    else if (choice == 3) {
        string direction;
        cout << "Convert: dec to hex or hex to dec? ";
        // Read full line to support inputs with spaces
        getline(cin, direction);

        if (direction == "dec to hex") {
            bool useLowercase;
            int decimalNumber;

            cout << "Use lowercase hex output? (true/false): ";
            // Read boolean input as 'true' or 'false'
            cin >> boolalpha >> useLowercase;
            cin.ignore(numeric_limits<streamsize>::max(), '\n');

            cout << "Enter a whole decimal number: ";
            cin >> decimalNumber;
            cin.ignore(numeric_limits<streamsize>::max(), '\n');

            cout << "\nOriginal Decimal: " << dec << decimalNumber << endl;

            // Output hexadecimal with 0x prefix, either lowercase or uppercase letters
            if (useLowercase)
                cout << "Hexadecimal (lowercase): " << showbase << hex << nouppercase << decimalNumber << endl;
            else
                cout << "Hexadecimal (UPPERCASE): " << showbase << hex << uppercase << decimalNumber << endl;

            // Reset output formatting to default
            cout << dec << nouppercase << noshowbase;
        }
        else if (direction == "hex to dec") {
            int hexNumber;

            cout << "Enter hexadecimal number (no prefix, e.g., 5d): ";
            // Read hex input (base 16)
            cin >> hex >> hexNumber;
            cin.ignore(numeric_limits<streamsize>::max(), '\n');

            cout << "\nOriginal Hexadecimal: " << showbase << hex << hexNumber << endl;
            cout << "Converted Decimal: " << dec << hexNumber << endl;

            // Reset formatting back to decimal, no base prefix, lowercase letters
            cout << dec << nouppercase << noshowbase;
        }
        else {
            cout << "Invalid conversion type entered.\n";
        }
    }

    else if (choice == 4) {
        char original[20];
        char copy[20];
        char newDate[20] = "";

        cout << "Enter a date in mm/dd/yyyy format: ";
        cin >> original;
        cin.ignore(numeric_limits<streamsize>::max(), '\n');

        // Copy the original string safely before tokenizing
        strcpy_s(copy, sizeof(copy), original);

        // Tokenize the string by '/' delimiter
        char* next_token = nullptr;
        char* month = strtok_s(copy, "/", &next_token);
        char* day = strtok_s(nullptr, "/", &next_token);
        char* year = strtok_s(nullptr, "/", &next_token);

        // Build new date format with dashes instead of slashes
        strcat_s(newDate, sizeof(newDate), month);
        strcat_s(newDate, sizeof(newDate), "-");
        strcat_s(newDate, sizeof(newDate), day);
        strcat_s(newDate, sizeof(newDate), "-");
        strcat_s(newDate, sizeof(newDate), year);

        cout << "Formatted Date: " << newDate << endl;
    }

    else {
        cout << "Invalid choice.\n";
    }

    // Ask the user if they want to run another operation or exit
    char again;
    cout << "\nWould you like to run another operation? (y/n): ";
    cin >> again;
    cin.ignore(numeric_limits<streamsize>::max(), '\n');  // Clear input buffer for next iteration

    if (again != 'y' && again != 'Y') {
        continueProgram = false;
    }
}

cout << "Program ended.\n";
return 0;

}