// This program does so and so ...
// Author: ....             Date: ...
// ...
// Metrowerks CodeWarrior version

#include<iostream>
using namespace std;

// declare global constants
const int UNITS_PER_ROOM  = 15;
const int FIXED_UNIT_COST =  5;
const int ADD_UNIT_COST   =  2;

int main()
{

// declare input variables
int nosRooms;
int oldMeterReading;
int newMeterReading;
char replyYorN;
int totalCostPence;
int totalCostPound;
int remainderPence;

   // Input Initial Data
   cout << "What is the number of rooms in your house? ";
   cin >> nosRooms; cout << endl;
   cout << "What is the OLD Meter reading? ";
   cin >> oldMeterReading;  cout << endl;
   cout << "What is the NEW Meter reading? ";
   cin >> newMeterReading;  cout << endl;

   // Perform Calculations 1
   // Calculate Number of Units for Fixed Charge
   int fixedUnits = UNITS_PER_ROOM * nosRooms;
   // Calculate Fixed Charge in Pence
   int fixedCost = fixedUnits * FIXED_UNIT_COST;
   // Calculate Actual Number of Units
   int actualUnits =  newMeterReading - oldMeterReading;
   // Is Actual Number than Fixed Charge Number?
   if (actualUnits > fixedUnits)
   {   // TRUE Case
       // Calculate Additional Number of Units
       int aboveUnits = actualUnits -  fixedUnits;
       // Calculate Total as Fixed Charge plus Additional Charge
       totalCostPence = fixedCost + aboveUnits * ADD_UNIT_COST;
   } 
   else
   {   // FALSE Case
       // Make Total equal to Fixed Charge
       totalCostPence = fixedCost;
   }
   // Is result in pounds and pence needed ?
   cout << "Do you want cost in pounds and pence (answer Y or N)? ";
   cin >> replyYorN; cout << endl;
   if (replyYorN == 'Y')
   {   // Case Yes
       // Perform Calculations 2
       // Find Number of Pounds in Total
       totalCostPound = totalCostPence / 100;
       // Find Remainder in Pence in Total 
       remainderPence = totalCostPence % 100;
       // Output Total in Pounds and Pence
       cout << "Total Due: " << totalCostPound << " pounds and "
            << remainderPence << " pence." << endl;
    }
    else if (replyYorN == 'N') 
    {   // Case No
        // Output the Total Cost in pence
        cout << "Total Due: " << totalCostPence << " pence." << endl;
    }
    else
    {   // Case neither Yes nor No - report Erroneous input
        cout << "Error in reply!" << endl;
    }
    cout << "the end of program" << endl;
   return 0;
}