// timeret.cpp
// a class that models a time data type
// member function to adds times, returns time value

#include <iostream.h>
#include <iomanip.h>   // for setw(), etc.
#include <conio.h>     //for getche()

class airtime
{
   private:
      int minutes;     // 0 to 59
      int hours;       // 0 t0 23

   public:
      void set()
      {
         char dummy;   // for colon

         cout << "Enter time (format 23:59): ";
         cin >> hours >> dummy >> minutes;
      }

      void display()
      {
         cout << hours  << ':'
              << setfill('0') << setw(2) << minutes;
      }

      airtime add(airtime at2)
      {
         airtime temp;
         temp.minutes = minutes + at2.minutes;   // add minutes
         temp.hours = hours + at2.hours;         // add hours

         if(temp.minutes > 59)                   // if carry,
         {
            temp.minutes = temp.minutes - 60;    // adjust minutes
            temp.hours = temp.hours + 1;         // and hours
         }

         if(temp.hours > 23)                     // if carry,
            temp.hours = temp.hours - 24;        // adjust hours

         return temp;
      }
};  // class airtime

void main()
{
   airtime t1, t2, t3;      // create three airtime variables
   char choice;

   do
   {
      cout << "For t1, ";
      t1.set();             // set t1
      cout << "For t2, ";
      t2.set();             // set t2

      t3 = t1.add(t2);      // add t1 and t2, result in t3

      cout << "t3 = ";
      t3.display();         // display t3

      cout << "\nDo another (y/n)? ";
      cin >> choice;
   } while(choice != 'n');

   // stop the flow on the monitor
   getch();

}  //end main