#include <iostream>

using namespace std;

// basic integer manipulation
void arithmetic()
{
    cout << "Please enter two integers, separated by a space.\n";
    int num1;
    int num2;
    cin >> num1;
    cin >> num2;

    cout << "Sum = " << (num1 + num2) <<
            "\nProduct = " << (num1 * num2) <<
            "\nDifference = " << (num1 - num2) <<
            "\nQuotient = " << (num1 / num2) << "\n";
    return;
}

// printing stuff with cout
void printing()
{
    cout << "Printing Exercise:\n";
    cout << "1 2 3 4\n";
    cout << "1 " << "2 " << "3 " << "4\n";
    cout.flush();
    for(int i = 0; i < 4; ++i)
    {
        cout << (i + 1) << " ";
    }
    cout << "\n";
    return;
}

// comparing ints
void comparing()
{
    cout << "Please enter two integers, separated by a space.\n";
    int num1;
    int num2;
    cin >> num1;
    cin >> num2;

    if(num1 < num2)
    {
        int tempNum = num1;
        num1 = num2;
        num2 = tempNum;
    }

    if(num1 == num2)
    {
        cout << num1 << " and " << num2 << " are equal.\n";
    }
    else
    {
        cout << num1 << " is larger, " << num2 << " is smaller.\n";
    }
    cout << "\n";
    return;
}

// three variable math
void arithmetic2()
{
    cout << "Please enter three integers, separated by spaces.\n";
    int num1;
    int num2;
    int num3;
    cin >> num1;
    cin >> num2;
    cin >> num3;
    cout << "Sum is " << num1 + num2 + num3 << "\n" <<
            "Average is " << (num1 + num2 + num3) / 3 << "\n" <<
            "Product is " << (num1 * num2 * num3) << "\n" <<
            "Smallest is " << min(num1, min(num2, num3)) << "\n" <<
            "Largest is " << max(num1, max(num2, num3)) << "\n";
    cout << "\n";
    return;
}

void circle()
{
    double PI = 3.14159;
    cout << "Please enter an integer.\n";
    int intNum;
    cin >> intNum;
    double dNum = static_cast<double>(intNum);
    cout << "A circle with radius " << intNum << " will have the following measurements:\n" <<
            "  Diameter\t" << 2 * intNum << "\n" <<
            "  Circumference\t" << dNum * PI << "\n" <<
            "  Area\t\t" << PI * (dNum * dNum) << "\n";
    return;
}

void digits()
{
    cout << "Please enter a five-digit integer.\n";
    int intNum;
    cin >> intNum;
    int subInt{0};
    string fourSpaces = "    ";

    cout << intNum / 10000 << fourSpaces;

    subInt = intNum / 10000;
    subInt *= 10000;
    cout << (intNum - subInt) / 1000 << fourSpaces;

    subInt = intNum / 1000;
    subInt *= 1000;
    cout << (intNum - subInt) / 100 << fourSpaces;

    subInt = intNum / 100;
    subInt *= 100;
    cout << (intNum - subInt) / 10 << fourSpaces;

    subInt = intNum / 10;
    subInt *= 10;
    cout << (intNum - subInt) << fourSpaces;

    return;
}

void bmi()
{
    int weight;
    int height;
    cout << "What is your weight in pounds?\n";
    cin >> weight;
    cout << "What is your height in inches?\n";
    cin >> height;

    cout << "Your BMI is " << ((weight * 703) / (height * height)) << ". But it's not a useful number. " <<
            "Get a hold of some body fat calipers if you want a set of meaningful measurements.\n";
}

int main()
{
    while(true)
    {
        // print menu
        cout << "1) Arithmetic\n" <<
                "2) Printing\n" <<
                "3) Comparing Integers\n" <<
                "4) Arithmetic 2\n" <<
                "5) Circle\n" <<
                "6) Digits of an Integer\n" <<
                "7) BMI Calculator\n" <<
                "0) Exit\n" <<
                "Please make your selection: ";


        // get user selection
        int selection{0};
        cin >> selection;

        // call function
        switch(selection)
        {
            case 1 : arithmetic(); break;
            case 2 : printing(); break;
            case 3 : comparing(); break;
            case 4 : arithmetic2(); break;
            case 5 : circle(); break;
            case 6 : digits(); break;
            case 7 : bmi(); break;
            case 0 : return 0;
            default : cout << "Unknown input\n";
        }
        cout << "\n\n";
    }
}