代写CS 586、代写c/c++，Java程序语音

日期：2023-02-08 09:33

HOMEWORK ASSIGNMENT #1

CS 586; Spring 2023

Due Date: February 9, 2023

Late homework 50% off

After February 13, the homework assignment will not be accepted.

This is an individual assignment. Identical or similar solutions will be penalized.

Submission: All homework assignments must be submitted on the Blackboard. The submission

must be as one PDF-file (otherwise, a 10% penalty will be applied).

PROBLEM #1 (40 points)

In the system, there exists a class BookSystem which keeps track of the prices of books in the

Book Market. This class supports the following operations: SetPrice(ISBN,price),

GetPrice(ISBN), BuyBook(ISBN), SellBook(ISBN), and NumBooks(ISBN). The

SetPrice(ISBN,price) operation set a new price for the book uniquely identified by ISBN. The

GetPrice(ISBN) operation returns the current price of the book identified by ISBN. The

BuyBook(ISBN) operation is used to buy a book identified by ISBN. The SellBook(ISBN)

operation is used to sell a book identified by ISBN. The operation NumBooks(ISBN) returns the

number of copies of a book identified by ISBN that are available in the system. Notice that each

book is uniquely identified by ISBN.

In addition, there exist user components in the system (e.g., UserA, UserB, etc.) that are

interested in watching the changes in book prices, especially, they are interested in watching the

out-of-range book price changes. Specifically, interested users may register with the system to be

notified when the price of the book of interest falls outside of the specified price range. During

registration, the user needs to provide the boundaries (lowprice, highprice) for the price range for

the specific book, where, lowprice is the lower book price and highprice is the upper book price

of the price range. At any time users may un-register when they are not interested any longer in

watching the out-of-range book price changes of a specific book. Each time when the price of a

book changes, the system notifies all registered users (for which the new book price is outside of

the specified price range) about the out-of-range book price change. Notice that if the book price

change is within the specified price range for a given user, this user is not notified about this

price change.

BookSystem

List:<ISBN,price,num>

SetPrice( )

GetPrice( )

BuyBook( )

SellBook()

NumBooks()

User A

DisplayPrice( )

User B

DisplayPrice( )

Design the system using the Observer pattern. Provide a class diagram for the system that

should include classes BookSystem, UserA, and UserB (if necessary introduce new classes and

operations). In your design, it should be easy to introduce new types of user components (e.g.,

UserC) that are interested in observing the changing prices of books. Notice that the components

in your design should be de-coupled as much as possible. In addition, components should have

high cohesion.

In your solution:

a. Provide a class diagram for the system. For each class list all operations with parameters and

specify them using pseudo-code. In addition, for each class provide its attributes/data

structures. Make the necessary assumptions for your design.

b. Provide two sequence diagrams showing:

How a user component registers to be notified about the out-of-range book price

change.

How the system notifies the registered user component about the out-of-range book

price change.

PROBLEM #2 (60 points)

The ATM component supports the following operations:

create() // ATM is created

card (int x, string y) //ATM card is inserted where x is a balance and y is a pin #

pin (string x) // provides pin #

deposit (int d); // deposit amount d

withdraw (int w); // withdraw amount w

balance (); // display the current balance

lock(string x) // lock the ATM, where x is a pin #

unlock(string x) // unlock the ATM, where x is pin #

exit() // exit from the ATM

A simplified EFSM model for the ATM component is shown on the next page.

Design the system using the State design pattern. Provide two solutions:

a decentralized version of the State pattern

a centralized version of the State pattern

Notice that the components in your design should be de-coupled as much as possible. In

addition, components should have high cohesion.

For each solution:

a. Provide a class diagram for the system. For each class list all operations with parameters and

specify them using pseudo-code. In addition, for each class provide its attributes and data

structures. Make the necessary assumptions for your design.

b. Provide a sequence diagram for the following operation sequence:

create(), card(900,”abc”), pin(“abc”), deposit(300), withdraw(110), exit()

When the EFSM model is “executed” on this sequence of operations, the following sequence

of transitions is traversed/executed: T1, T2, T19, T14, T7, T5

check pin

ready

overdrawn

idle

pin( x )[ (x==pn)&&(b>=1000) ] /

display menu

pin( x )[ (x!=pn)&&(attempts==3) ] /

eject card

pin( x )[ (x!=pn)&&(attempts<3) ] /

attempts++

pin( x )[ (x==pn)&&(b<1000) ] /

display menu

locked

unlock( x )[ (x==pn)&&(b<1000) ]

unlock( x )[ (x==pn)&&(b>=1000)

EFSM of ATM

card( x, y ) / b=x; pn=y;

attempts=0

create

balance / display balance b

withdraw( w )[ b-w>=1000 ] /

b=b-w

deposit( d ) / b=b+d

withdraw( w )[ (b-w<1000)&&(b-w>0) ] /

b=b-w-10

exit / eject card lock( x )[ x==pn ]

deposit( d )[ b+d>=1000 ] /

b=b+d

deposit( d )[ b+d<1000 ]

/ b=b+d-10

balance / display balance b

exit / eject card

lock( x )[ x==pn ]