void menuOptions()
{
    cout << "Enter the corresponding number with what you want to do with this: \n";
    cout << "1: Double the number.\n";
    cout << "2: Reverse the digits of the number.\n";
    cout << "3: Raise the number to the power of 2, 3, or 4.\n";
    cout << "4: Sum the digits of the number.\n";
    cout << "5: If the number is a two digit number, then raise the first digit to the power of the second digit.\n";
    cout << "6: If the number is a three digit number and the last digit is less than or equal to 4, then raise the first two digits to the power of the last digit.\n";
    cout << "-1: Reset Random Number.\n\n";
    cout << "0: Terminate the program.\n\n";
    cout << "Enter: ";
}

//Random Number Generator
int randomNumGenerator(int randNum)
{
    while (randNum < 10 || randNum > 100)
    {     srand(static_cast <unsigned int> (time(0)));
        randNum = rand() % 100;
    }
    return randNum;
}

//Choice 1:
long int funcOne(long int doubledNum, long int currentNum)
{
    doubledNum = currentNum * 2;
        return doubledNum;
}

//Choice 2:
long int funcTwo(long int reversedNum, long int currentNum)
{
    while(currentNum != 0.0)
    {
        int remainder = currentNum % 10;
        reversedNum = reversedNum * 10 + remainder;
        currentNum /= 10;
    }
    return reversedNum;
}

//Choice 3:
long double funcThree(long double poweredNum, int choice2, long int currentNum)
{
    switch(choice2)
    {
        case 2:
            poweredNum = pow(currentNum, 2);
            cout << currentNum << " squared = ";
            break;
        case 3:
            poweredNum = pow(currentNum, 3);
            cout << currentNum << " cubed = ";
            break;
        case 4:
            poweredNum = pow(currentNum, 4);
            cout << currentNum << " to the 4th power = ";
            break;
        default:
            cout << "Not an option....";
            return currentNum;
    }
    return poweredNum;
}

//Choice 4
long int funcFour(long int sumOfNum, long int currentNum)
{
    while ( currentNum > 0 )
    {
        sumOfNum += currentNum % 10;
        currentNum /= 10;
    }
    return sumOfNum;
}

//Choice 5
long double funcFive(string firstToSecond, string num1, string num2, long double twoDigitPowered, long int currentNum)
{
    firstToSecond = to_string(currentNum);
    if(firstToSecond.length() != 2)
    {
        cout << "Not a 2-digit number\n\n";
        cout << "Current number: ";
        return currentNum;
    }
    else if(firstToSecond.length() == 2)
    {
        num1 = firstToSecond.substr(0,1);
        num2 = firstToSecond.substr(1,1);
        int numb1 = stoi(num1);
        int numb2 = stoi(num2);
        twoDigitPowered = pow(numb1, numb2);
    }
    return twoDigitPowered;

}

//Choice 6
long double funcSix(string secondToThird, long double threeDigitPowered, long int currentNum)
{
    secondToThird = to_string(currentNum);
    
    unsigned long pos1 = secondToThird.length() - 1;
    string substr =  secondToThird.substr(pos1, 1);
    if(secondToThird.length() != 3)
    {   cout << "Not a 3-digit number\n\n";
        cout << "Current number: ";
    return currentNum;}
    else if(secondToThird.length() == 3 && secondToThird.length() <= 4)
    {
        string num1 = secondToThird.substr(0,2);
        string num2 = secondToThird.substr(2,1);
        int number1 = stoi(num1);
        int number2 = stoi(num2);
        threeDigitPowered = pow(number1, number2);          
    }
    return threeDigitPowered;
}


//Add Ten
long int addTen(long int currentNum, long int add)
{
    if (currentNum < 10)
    {
        add = currentNum + 10;
        cout << "Adding 10 = " << add << "\n\n";
        currentNum = add;
    }
    return currentNum;
}

//Test Prime
void isPrime(long int currentNum, int divisor)
{
    if (currentNum >= 2)
    {    for (divisor = 2; divisor <= currentNum / 2; divisor++)
        if (currentNum % divisor == 0)
            break;
        
        if ((currentNum > 1) && (!(divisor <= currentNum / 2)))
            
            cout << "The number "<< currentNum
            << " is a prime number.\n\n";
            
            else
            cout << "The number "<< currentNum
            << " is NOT a prime number.\n\n";
    }

}

void cleanup()
{
    cin.clear();
    cin.ignore(INT_MAX, '\n');
    //system("cls"); for Windows
}