using System;

​

public class Booking {

​

  public virtual void GenerateTicket (float P, String Source, String Destination)

  {

    float price = 1000.0f;

​

    //PRE CONDITION TO CHECK NULL

    if ((Source == null) || (Destination == null))

​

    {

​

      Console.WriteLine("Please choose a Source and Destination ");

​

      throw new ArgumentOutOfRangeException("", "No Source and Destination ");

    }

​

      price = price - P * 0.1f;

​

      //Price calculation on the number of people

​

      //POST CONDITION TO VERIFY NO. OF PASENGERS ( ATLEAST 1)

      if (P >= 1) {

​

        Console.WriteLine("THE TICKETS WILL COST : " + price + "$");

        //reduce the cost if more than 1 people book the service

​

      } else {

​

        Console.WriteLine("ATLEAST ONE PASSENGER REQ");

​

      }

​

    }

​

  }

​

  public class UltraLuxuryBooking: Booking {

​

      public override void GenerateTicket(float P, String Source, String Destination) {

        float price = 1200.0f ; // this will be higher than normal booking

​

        //PRE CONDITION TO CHECK NULL

​

        if ((Source == null) || (Destination == null))

​

        {

​

          Console.WriteLine("Please Fill out a source and destination ");

          throw new ArgumentOutOfRangeException("", "Source or Destination cannot be null ");

​

          }

​

          price = price - P * 0.1f; //Price calculation

​

          //POST CONDITION TO VERIFY NO. OF PASENGERS ( ATLEAST 1)

          if (P >= 1) {

​

            Console.WriteLine("THE TICKETS WILL COST : " + price + "$");

            //PRINTING COST

​

          } else

​

          {

​

            Console.WriteLine("ATLEAST TWO PASSENGERS REQ");

​

          }

​

        }

​

      }

​

      public class Family_Holiday_Booking: Booking {

​

        public override void GenerateTicket(float P, String Source, String Destination) {

          float price = 1020.0f;

​

          //PRE CONDITION TO CHECK NULL

​

          if ((Source == null) || (Destination == null))

​

          {

​

            Console.WriteLine("Source/Destination cannot be null");

​

            throw new ArgumentOutOfRangeException ("", "Source or Destination cannot be null ");

​

            }

​

            price = price + P * 300; //Price calculation

​

            //POST CONDITION TO VERIFY NO. OF PASENGERS ( ATLEAST 1 max of 5)

          if (P >= 2) {

​

            Console.WriteLine("THE TICKETS WILL COST : " + price + "$");

            //PRINTING COST

​

          } else

​

          {

​

            Console.WriteLine("Atleast 2 People Required");

​

          }

​

        }

​

      }

​

      public class MainClass {

​

        public void Main() {

​

          String name;

          int passengers; // number of people

          int choice; //

​

          Console.WriteLine("ENTER YOUR NAME:");

          name = Console.ReadLine();

​

          Console.WriteLine("ENTER NUMBER OF PASSENGERS:");

          passengers = Convert.ToInt32(Console.ReadLine());

​

          Console.WriteLine("1) Luxury ");

          Console.WriteLine("2) Ultra Luxury");

          Console.WriteLine("3) Family Holiday");

​

          choice = Convert.ToInt32(Console.ReadLine());

​

          try {

​

            switch (choice) {

​

            case 1:

              Booking book_obj = new Booking();

​

              book_obj.GenerateTicket(passengers, "Delhi", "Bangalore");

​

              break;

​

            case 2:

              book_obj = new UltraLuxuryBooking();

​

              book_obj.GenerateTicket(passengers, "Kolkata", "Delhi");

​

              break;

​

            case 3:

              book_obj = new Family_Holiday_Booking();

​

              book_obj.GenerateTicket(passengers, "Mumbai", "Faridabad");

​

              break;

​

            }

​

          } catch (ArgumentOutOfRangeException outOfRange) {

​

            Console.WriteLine("Error: {0}", outOfRange.Message);

          }

​

        }

​

      }