The following program represents tickets for sporting events sold by the university stadium. Tickets are less expensive when ordered in advance and students get a $50\%$ discount on advance tickets. Several classes work together via inheritance to provide this functionality used by the ticket booth operators. Read all of the classes before typing in the missing code.

$=====$Ticket Superclass$=====$

public

class Ticket $\{$

protected int serialNum;

private static num $=0$;

public Ticket$()\{$

$=$ getNextSerialNum$()$;

$\}$

public abstract double getPrice$()$;

public

toString$()\{$

"Number: $"+$ serialNum $+"$

Price: $"+$ getPrice$()$;

$\}$

private static int getNextSerialNum$()\{$

num$++$;

serialNum $=$

;

return serialNum;

$\}$

$\}$

$=====$Walkup Subclass$=====$

public class

extends Ticket$\{$

private double price $=20\mathrm{.}00$;

public Walkup$()\{$

super$()$;

$\}$

public

getPrice$()\{$

return price;

$\}$

$\}$

$=====$Advance Subclass$=====$

public class Advance extends Ticket$\{$

private double price;

private int days;

public Advance$($int d$)\{$

;

days $=$

;

$\}$

public double getPrice$()\{$

if $($days $>=10)$

price $=10\mathrm{.}0$;

price $=15\mathrm{.}0$;

return price;

$\}$

$\}$

$=====$StudentAdvance Subclass$=====$

public class StudentAdvance

$\{$

public StudentAdvance$($int d$)\{$

super$($d$)$;

$\}$

public double getPrice$()\{$

return

$.$getPrice$()/2$;

$\}$

public String toString$()\{$

return super.toString$()+"$

$($student ID required$)"$;

$\}$

$\}$

$=====$Driver Class TicketBooth$=====$

import java.util.Scanner;

public class TicketBooth $\{$

public static void main$($String$[]$ args$)\{$

Scanner scan $=$

;

ArrayList tix $=$ new ArrayList$()$;

int choice, days;

temp;

System.out.println$("$Welcome ticket booth operator!

Just type the ticket type number to generate a ticket."$)$;

System.out.println$("$Menu:

$1)$Walkup Ticket

$2)$Advance Ticket

$3)$Student Advance Ticket

$0)$Quit$")$;

choice $=$

;

scan.nextLine$()$;

while $($

$!=0)\{$

if $($choice $>1)\{$

System.out.println$("$Number of days until the show?"$)$;

$=$ scan.nextInt$()$;

scan.nextLine$()$;

if $($choice $==2)\{$

temp $=$ new

$($days$)$;

$\}$ else $\{$

temp $=$ new StudentAdvance$($days$)$;

$\}$

$\}$ else $\{$

temp $=$ new Walkup$()$;

$\}$

tix.add$($

$)$;

System.out.println$($temp$)$;

System.out.println$("$Welcome ticket booth operator!

Just type the ticket type number to generate a ticket."$)$;

System.out.println$("$Menu:

$1)$Walkup Ticket

$2)$Advance Ticket

$3)$Student Advance Ticket

$0)$Quit$")$;

choice $=$ scan.nextInt$()$;

scan.nextLine$()$;

$\}$

$\}$

$\}$