//This program displays a menu and asks the user to make a 
//selection. A do-while loop repeats the program until the
//user selects item 4 from the menu.
#include <iostream>
#include <iomanip>
using namespace std;

int main ()
{
	//Constants for menu choices
	const int ADULT_CHOICE = 1,
			  CHILD_CHOICE = 2,
			  SENIOR_CHOICE = 3,
			  QUIT_CHOICE =4;
	
	//Constants for membership rates
	const double ADULT = 40.0,
				 CHILD = 20.0,
				 SENIOR = 30.0;
	
	//Variables 
	int choice;			//Menu choice
	int months;			//Number of months
	double charges;		//Monthly charges
	
	//Set up numeric output formatting.
	cout << fixed << showpoint << setprecision(2);
	
	do
	{
		//Display the menu.
		cout << "\n\t\tHealth Club Membership Menu\n\n"
			 << "1. Standard Adult Membership\n"
			 << "2. Child Membership\n"
			 << "3. Senior Citizen Membership\n"
			 << "4. Quit the Program\n\n"
			 << "Enter your choice: ";
		cin  >> choice;
		
		//Validate the menu selection.
		while (choice < ADULT_CHOICE || choice > QUIT_CHOICE)
		{
			cout << "Please enter a valid menu choice: ";
			cin >> choice;
		}
		
		//Validate and process the user's choice.
		if (choice != QUIT_CHOICE)
		{
			//Get the number of months.
			cout << "For how many months? ";
			cin >> months;
			
			//Respond to the user's menu slesction.
			switch (choice)
			{
				case ADULT_CHOICE:
					charges = months * ADULT;
					break;
				case CHILD_CHOICE:
					charges = months * CHILD;
					break;
				case SENIOR_CHOICE:
					charges = months * SENIOR;
			}
			
			//Display the monthly charges.
			cout << "The total charges are $"
				 << charges << endl;
		}	
	}while (choice != QUIT_CHOICE);
	return 0;
}