Programming Challenge 4.20 - Speed Of Sound

/* Speed Of Sound - This program displays a menu, allowing the user to
   select air, water or steel. After the user has made a selection, he
   or she should be asked to enter the distance a sound wave will travel
   in the selected medium. The program will then display the amount of
   time it will take. The answer is rounded to four decimal places.
  
   Medium                        Speed
   Air                             1,100 feet per second
   Water                         4,900 feet per second
   Steel                        16,400 feet per second
  
   Input Validation: The user can only select menu items 1 through 4.
   Distances of 0 or less are not accepted. */

#include "Utility.h"

int main()
{
    /* Constants for menu */
    const int TOC_Air = 1,
              TOC_Water = 2,
              TOC_Steel = 3;

    /* Constants for feet per second */
    const double AIR_FPS = 1100.0,
                 WATER_FPS = 4900.0,
                 STEEL_FPS = 16400.0;

    /* Hold menu choice */
    int choice = 0;

    /* Hold input for, distance in feet, medium, amount of time */
    double distance = 0,
           amountOfTime = 0;
          
    /* Display the menu */
    cout << "\t\tSpeed Of Sound - Please select Air, Water or Steel as "
         << "medium.\n\n"
         << "1. Air\n"
         << "2. Water\n"
         << "3. Steel\n"
         << "4. Quit\n";
    cin >> choice;

    /* Format the output and display the result */
    cout << fixed << showpoint << setprecision(4);

    /* Choices */
    switch (choice)
    {
    case 1:
        /* Display the user's choice and Ask the user to enter distance */
        cout << "\t\tAir\n\n"
             << "Enter a distance in feet the sound waves travel through "
             << "this medium: ";
        cin >> distance;
       
        /* Calculation */
        amountOfTime = (distance / AIR_FPS);

        /* Input validation */
        if (distance <= 0)
        {
            cout << "You entered an invalid distance. Only distances above 0\n"
                << "are allowed!.\n";
        }
        else
        {
            /* Display the result */
            cout << "It takes sound waves " << amountOfTime << " ft/sec "
                << "to travel a distance of " << setprecision(2) << distance
                << " ft. through air.\n";
        }
        break;

    case 2:
        cout << "\t\tWater\n\n"
             << "Enter a distance in feet the sound waves travel through "
             << "this medium: ";
        cin >> distance;

        amountOfTime = (distance / WATER_FPS);

        if (distance <= 0)
        {
            cout << "You entered an invalid distance. Only distances above 0\n"
                << "are allowed!.\n";
        }
        else
        {
            cout << "It takes sound waves " << amountOfTime << " ft/sec "
                << "to travel a distance of " << setprecision(2) << distance
                << " ft. through water.\n";
        }
        break;

    case 3:
        cout << "\t\tSteel\n\n"
             << "Enter a distance in feet the sound waves travel through "
             << "this medium: ";
        cin >> distance;
   
        amountOfTime = (distance / STEEL_FPS);

        if (distance <= 0)
        {
            cout << "You entered an invalid distance. Only distances above 0\n"
                << "are allowed!.\n";
        }
        else
        {
            cout << "It takes sound waves " << amountOfTime << " ft/sec "
                << "to travel a distance of " << setprecision(2) << distance
                << " ft. through steel.\n";
        }
        break;

    case 4:
        cout << "\t\tQuit\n\n"
             << "Exiting program ...\n";
        break;

    default:
        cout << "You entered an invalid menu-item. Please choose 1 through 4.\n";
    }

    pauseSystem();
    return 0;
}