// This program displays a menu and asks the user to make a
// selection. A switch statement determines which item
// the user has chosen.
#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
   int choice;       // Menu choice
   int months;       // Number of months
   double charges;   // Monthly charges

   // Constants for membership rates
   const double ADULT = 40.0;
   const double SENIOR = 30.0;
   const double CHILD = 20.0;

   // Display the menu and get a choice.
   cout << "\t\tHealth Club Membership Menu\n\n";
   cout << "1. Standard Adult Membership\n";
   cout << "2. Child Membership\n";
   cout << "3. Senior Citizen Membership\n";
   cout << "4. Quit the Program\n\n";
   cout << "Enter your choice: ";
   cin >> choice;
   
   // Validate and process the menu choice.
   if (choice >= 1 && choice <= 3)
   {
      // Get the number of months.
      cout << "For how many months? ";
      cin >> months;
      
      // Set the numeric output formatting.
      cout << fixed << showpoint << setprecision(2);
      
      // Respond to the user's menu selection.
      switch (choice)
      {
         case 1:  charges = months * ADULT;
                  break;
         case 2:  charges = months * CHILD;
                  break;
         case 3:  charges = months * SENIOR;
      }
      
      // Display the monthly charges.
      cout << "The total charges are $";
      cout << charges << endl;
   }
   else if (choice != 4)
   {
      cout << "The valid choices are 1 through 4. Run the\n";
      cout << "program again and select one of those.\n";
   }
   return 0;
}