2 class diagrams We are about to develop a ticketing system for sports teams. There are three types of customers: visitors, registered viewers and VIPs, with different prices. To buy a ticket, a customer first types in his/her id from the welcome screen, if the id is on the blacklist, the system displays a warning message then returns to the welcome screen. If the id cannot be found in DB the customer is assumed to be a visitor and go directly to the ticket order screen (remember a visitor must pay more). Otherwise the customer is then asked to type in his/her password, if the password does not match the one in the system, the customer is transferred to the ticket order subsystem as a visitor. If the password matches, she enters the ticket order screen. In the ticket order screern the customer is asked to type in the type of ticket to be purchased. There are two types of tickets: one-time and seasonal. A visitor can only purchase the former, the other two can buy both with different prices. The customer may either choose one (s/he is allowed) and pay for it for as many times as s/he wants to or quit from the system. The system then returns to the welcome screen. A registered viewer who purchased more than $500 worth cumulatively will be promoted to a VIP, A VIP who hasn't made any purchase in the last year is demoted to a registered viewer (a) (5 pts) Draw the E-R diagram for this system (reminder: don't over-work). (b) (10 pts) Draw the Petri-net for this system 2 class diagrams We are about to develop a ticketing system for sports teams. There are three types of customers: visitors, registered viewers and VIPs, with different prices. To buy a ticket, a customer first types in his/her id from the welcome screen, if the id is on the blacklist, the system displays a warning message then returns to the welcome screen. If the id cannot be found in DB the customer is assumed to be a visitor and go directly to the ticket order screen (remember a visitor must pay more). Otherwise the customer is then asked to type in his/her password, if the password does not match the one in the system, the customer is transferred to the ticket order subsystem as a visitor. If the password matches, she enters the ticket order screen. In the ticket order screern the customer is asked to type in the type of ticket to be purchased. There are two types of tickets: one-time and seasonal. A visitor can only purchase the former, the other two can buy both with different prices. The customer may either choose one (s/he is allowed) and pay for it for as many times as s/he wants to or quit from the system. The system then returns to the welcome screen. A registered viewer who purchased more than $500 worth cumulatively will be promoted to a VIP, A VIP who hasn't made any purchase in the last year is demoted to a registered viewer (a) (5 pts) Draw the E-R diagram for this system (reminder: don't over-work). (b) (10 pts) Draw the Petri-net for this system