base.h

飞机场模拟系统

 
#ifndef   _BASE_H_
#define   _BASE_H_

void initialize(int &end_time, int &queue_limit,
                double &arrival_rate, double &departure_rate)
/*
Pre:  The user specifies the number of time units in the simulation,
      the maximal queue sizes permitted,
      and the expected arrival and departure rates for the airport.
Post: The program prints instructions and initializes the parameters
      end_time, queue_limit, arrival_rate, and departure_rate to
      the specified values.
Uses: utility function user_says_yes
*/

{
   cout << "This program simulates an airport with two runways." << endl
        << "One plane can land or depart in each unit of time." << endl;
   cout << "Up to what number of planes can be waiting to land "
        << "or take off at any time? " << flush;
   cin  >> queue_limit;

   cout << "How many units of time will the simulation run?" << flush;
   cin  >> end_time;

   bool acceptable;
   do {
      cout << "Expected number of arrivals per unit time?" << flush;
      cin  >> arrival_rate;
      cout << "Expected number of departures per unit time?" << flush;
      cin  >> departure_rate;
      if (arrival_rate < 0.0 || departure_rate < 0.0)
         cerr << "These rates must be nonnegative." << endl;
      else
         acceptable = true;

      if (acceptable && arrival_rate + departure_rate > 1.0)
         cerr << "Safety Warning: This airport will become saturated. " << endl;

   } while (!acceptable);
}

void run_idle(int time)
/*
Post: The specified time is printed with a message that the runway is idle.
*/
{
   cout << time << ": Runway is idle." << endl;
}

#endif