Question $1$

The UML class diagram is an initial design of classes for a conference registration application.

There are three types of registration allowed for the conference: standard registration, student registration and invited guests registration. The standard registration fee is the standard fee $($stored in STANDARD$\_$FEE$).$ For those registered as students, the conference fee is half the price of the standard registration fee. For those registered as guests, the conference fee is $10\%$ of the standard registration fee.

An instance of RegistrationList contains a list of Registration$*.$ No two registrations are allowed to have attendees with the same e$-$mail addresses, unless the names are different. You should be able to query a RegistrationList whether a person $($by the name$)$ is already registered for the conference. A RegistrationList can also return the number of attendees that are registered for the conference from an institution. Similarly, you can request the total registration fees for a type $("$Registration$",$ "StudentRegistration", "GuestRegistration" or "All"$)$ of registration. You are expected to use Qt$\text{'}$s metaobject system to access the type of a Registration in RegistrationList.

Write a GUI application that allows users to register for a conference. The GUI should display the current list of registrations, including the respective registration fees, in the RegistrationList at all times, using a table widget. The interface should also allow users to request and view the results of the various operations supported by the RegistrationList class.

You are allowed to add new features to the classes given in the UML diagram, although you are not allowed to delete or change the given functions. You can decide on the design of the GUI, $$nd it c$$n b$$ d$$n$$ m$$ually or using Qt Designer. You $$r$$ expected t$$ followw good programming principles.