CSCI 1300 - Starting ComputingInstructor: FlemingHomework 8: Part III**This assignment is a project!Due Monday, November 5th, by 11:55 pm**No bonus for project II !This assignment is due Monday, November 5th, by 11:55 pm● All components (Cloud9 workspace, moodle quiz attempts, and zip file) must becompleted and submitted by Monday, November 5th, by 11:55 pm for yourhomework to receive points.Objectives:● Practice implementing classes● Develop proper techniques for object-oriented programming● Manipulate arrays of objects● Implement classes which have objects from other classes as data membersProblem Set **All the examples and values used in examples are imaginary and randomly generated.In part 3 you will streamline your implementation with the addition of a library class. Thisclass will centralize many of the methods you implemented in parts 1 and 2 and providemore functionality, including the ability to recommend books based on the similarity oftwo users.Specifications● Create a new class Library. Define the class in a header file and implement theclass in a cpp file.● The Book and User classes from Homework 7 will be part of Homework 8 as well● In main() create an instance of Library object and a menu as specified● Students should have seven files (Book.h, Book.cpp, User.h, User.cpp, Library.h,Library.cpp, Hmwk8.cpp)● The name of each member function should be exactly as specified. If you modifythe function names your solution will not pass the autograder.Library Class**You should have separate files for class definition and implementation: Library.h and Library.cppCreate a class Library, with separate interface and implementation, comprised of thefollowing attributes:Data members (private):Book array: books An array of Book objectsUser array: users An array of User objectsint: numBooks Number of books in the database (library)int: numUsers Number of users in the database (library)int: sizeBook The capacity of the books array (200). Constantint: sizeUser The capacity of the users array (200). ConstantMember functions (public):Default constructor Sets both numBooks and numUsers to value 0.readBooks(string) Takes a string (the name of the file to be read) andpopulates the books array. Returns the totalnumber of books in books array as an integerreadRatings(string) Takes a string (the name of the file to be read) andpopulates the users array. Returns the totalnumber of users in users array as an integerprintAllBooks() Prints all books stored in books array.getCountReadBooks(string) Takes a string (username) and returns the numberof books read by that user as an integer.calcAvgRating(string) Takes a string (the title of a book) and returns theaverage rating of the specified book as a doubleaddUser(string) Takes a string (username) and returns True if theusername is successfully added to the database.Otherwise, returns False.checkOutBook(string,string, int)Takes two strings and an integer for username, titleof book, and a new rating, respectively (in thisorder). Returns True if the rating is successfullyupdated. Otherwise, returns False.viewRatings(string) Takes a string (username) and prints all the booksa user has provided ratings for.getRecommendations(string) Takes a string username and prints the first 5 bookrecommendations from the most similar (other)user.It is advisable to write your own test cases for each class. Test your class in Cloud9 beforesubmitting to the autograder, as the autograder has a submission limit of 20 tries every 24hours.Problem 1 - the member function readBooksThe member function readBooks populates an array of Book objects with the title andauthor data found in a file similar to the file books.txt. The array of Book objects is one ofthe data members of the Library class. This function should:● Accept one input argument:○ string: the name of the file to be read● Use ifstream, split(), and getline to read and parse data from the file.● For each line in the file:○ fill in the author and title data members for a Book object, at theappropriate index in the array of Book objects.● Also:○ Update the total number of books in the system(from all the files read sofar, see the “Important” note below)● Return the total number of books in the system, as an integer.● If the file contains more books than “empty” slots available in the books array,only write enough books so that you do not exceed the capacity of the array.● If the file cannot be opened, return -1Important: when testing your readBooks function, make sure it supports multiplereads from different .txt files in a row. For example, you should be able to call thefunction to read the file books1.txt , and then call the function again to read the filebook2.txt. The result should be an array of Book objects, with the books from the firstfile, followed by the books from the second file.Problem 2 - the member function readRatingsThe member function readRatings populates an array of User objects with the user nameand the ratings data found in a file similar to the file ratings.txt. The array of Userobjects is one of the data members of the Library class. This function should:● Accept one input argument:○ string: the name of the file to be read● Use ifstream, split(), and getline to read and parse data from the file.● For each line in the file:○ fill in the username and ratings data members for a User object, atthe appropriate index in the array of User objects.● Also:○ Update the total number of users in the system(from all the files read sofar, see the “Important” note below)● Return the total number of users in the system, as an integer.● If the file contains more users than “empty” slots available in the users array,only write enough books so that you do not exceed the capacity of the array.● If the file cannot be opened, return -1Important: when testing your readRatings function, make sure it supports multiplecalls in a row. For example, you should be able to call the function to read the fileratings1.txt , and then call the function again to read the file ratings2.txt. The resultshould be an array of User objects, with the users from the first file, followed by theusers from the second file.Expected output:cynthia...diane...joan...barbara...(etc.)Problem 3 - the member function printAllBooksThe member function printAllBooks prints the list of all the books in the database(library). This function should:● Accept no arguments● Not return anything● If the program has not read any books files or any ratings files, print the followingmessage:Database has not been fully initialized● Otherwise, print “Here is a list of books”, followed by each book in thefollowing format by Expected output (assuming you have read the data only from books.txt)Here is a list of booksThe Hitchhikers Guide To The Galaxy by Douglas AdamsWatership Down by Richard AdamsThe Five People You Meet in Heaven by Mitch AlbomSpeak by Laurie Halse Anderson(etc.)Problem 4 - the member function getCountReadBooksThe member function getCountReadBooks determines how many books a particularuser has read and reviewed. This function should:● Accept one argument:○ string: username● Return the number of books read/reviewed by the specified user, as an integer.● If the program has not read any books files or any ratings files, it should return -1after printing the following message:Database has not been fully initialized● If the database is initialized (at least one file of books and at least one file ofratings has been read), but the user name is not found, return -2 after printing thefollowing message : does not exist in the databaseProblem 5 - the member function calcAvgRatingThe member function calcAvgRating returns the average (mean) rating for a particularbook. This function should:● Accept one argument:○ string: book title● Return the average rating of the specified book as a double● If the program has not read any books files or any ratings files, it should return -1after printing the following message:Database has not been fully initialized● If the database is initialized (at least one file of books and at least one file ofratings has been read), but the book is not found, return -2 after printing thefollowing message: does not exist in the databaseNote: Books that haven’t been read shouldn’t be counted in calculating the average.Problem 6 - the member function addUserThe member function addUser adds a new user to the database. This function should:● Accept one argument:○ string: user name● Fill in the username and ratings data members for a User object, at theappropriate index in the array of User objects. :● Update the total number of users in the system(from all the files read so far, seethe “Important” note below)● The name of the user is case insensitive (e.g. Ben. BEN, ben are all same asben)● Return True if the user is successfully added.● If the user already exists in the database, print the following message and returnFalse already exists in the database● If the database is full (the array of User objects is full)CSCI 1300作业代写、代做C/C++程序作业、代写C/C++实验作业、代做Starting Computing留学, print the followingmessage and return FalseDatabase fullProblem 7 - the member function checkOutBookThe member function checkOutBook updates the rating of the book for the user. Thisfunction should:● Accept three arguments in this order○ string : username○ string: book title○ int: new rating● Find the index of the user and the index for the book, then update the new ratingif the new rating value is valid. The rating scheme follows the one provided inhomework 6.Rating Meaning0 Did not read1 Hell No - hate it!!2 Don’t like it.3 Meh - neither hot nor cold4 Liked it!5 Mind Blown - Loved it!● If the program has not read any books files or any ratings files, it should returnFalse after printing the following message:Database has not been fully initialized● If the rating is successfully updated, then returns True. Otherwise, it shows one(or more) of the following messages in the given order and return False.● If the user is not found: does not exist in the database● If the title is not found: does not exist in the database● If the rating value is not valid: is not validProblem 8 - the member function viewRatingsThe member function viewRatings prints all the books a user has provided ratingsfor. Recall that a rating of 0 means a user has not rated that book and hence shouldn’tbe displayed. This function should:● Accept one input argument:○ string: username● Not return anything.● If the program has not read any books files or any ratings files, print the followingmessage:Database has not been fully initialized● If the user is not found in the database, print: does not exist in the database● If the user is found in the database, but has not rated any books, print: has not rated any books yet● If the user exists in the database, and it has rated at least one book, display theuser’s ratings in the following format:Expected output (assuming you have read the data only frombooks.txt,ratings.txt)Here are the books that megan ratedTitle : The Hitchhikers Guide To The GalaxyRating : 5-----Title : The Five People You Meet in HeavenRating : 2-----(...)Problem 9 - the member function getRecommendationsThe member function getRecommendations will recommend book titles a user mightenjoy, based on the user’s similarity of ratings with another user. This function should:● Accept one input argument:○ string: username● Not return anything.● If the program has not read any books files or any ratings files, it should print thefollowing message:Database has not been fully initialized● If the database is initialized (at least one file of books and at least one file ofratings has been read), but the user name is not found, it should print thefollowing message : does not exist in the databaseTo generate recommendations for a user, for example the user named “ben”:1. Find the most similar user to “ben”. Let’s say we found “claire” to be mostsimilar.2. Recommend to “ben” the first 5 books in the database “claire” has rated with arating of 3, 4 or 5, that “ben” has not yet read (rating 0)○ If there are less than 5 books to recommend, recommend as many aspossible. “ben” will be presented with 0 to 5 recommendations.To find out who the most similar user is to “ben”, we need to compare “ben”’s ratingswith the ratings from all the other users. We need to look at differences in the ratingvalues between the two users for a certain book, add them up, and come up with asimilarity value. The user who has the smallest similarity value, will be the user mostsimilar to “ben”.Note 1: A new user, who has not rated any books, cannot be chosen as the mostsimilar user. We recommend you use the getCountReadBooks function to weed outthe new users.Note 2: You can assume there will be no ties between two users.The similarity metric you should use is the sum of squared differences (SSD).The sum of squared differences is calculated by summing the squares of thedifferences between corresponding elements in two ratings arrays from two users.Follow the example below.Let A represent bens ratings, and B represent claires ratings.Ai is bens rating for book i, and Bi is claires rating for book iSSD = ∑(A )ii ? Bi2For example:john′s ratings : [0, 1, 3, 5]claire′s ratings : [3, 0, 5, 0]SSD = (0 ? 3) (1 0) (3 5) (5 0) 2 + ? 2 + ? 2 + ? 2SSD = (? 3) (1) (? ) (5) 2 + 2 + 2 2 + 2SSD = 9 + 1 + 4 + 25 = 39Users with very different ratings will get a high SSD.john′s ratings : [5, 1, 0, 0, 5]david′s ratings : [1, 5, 0, 5, 1]SSD = (5 ? 1) (1 5) (5 0) 2 + ? 2 + ? 2 + (5 ? 1) 2SSD = 4 4 5 2 + 2 + 2 + 4 2SSD = 16 + 16 + 25 + 16 = 73Two users with very similar ratings will get a low SSD.john′s ratings : [5, 0, 5, 3]claire′s ratings : [5, 0, 4, 2]SSD = (5 ? 5) (5 4) (3 2) 2 + ? 2 + ? 2SSD = 0 1 1 2 + 2 + 2SSD = 0 + 1 + 1 = 2For example (this example is different than the data in ratings.txt):Lets say were generating recommendations for John. Here are the books:Douglas Adams,The Hitchhikers Guide To The GalaxyRichard Adams,Watership DownMitch Albom,The Five People You Meet in HeavenLaurie Halse Anderson,SpeakLiz: [5, 0, 5, 3]John: [5, 0, 3, 0]David: [4, 1, 0, 5]To generate recommendations for John:1. find the most similar userJohn has a SSD of 13 with Liz and an SSD of 36 with David, so John is moresimilar to Liz.2. find 10 books Liz (the most similar user) has rated as a 3, 4, or 5 that Johnhas not yet read (rating 0)We look at Lizs list to find books that shes rated that John hasnt rated yet:? Liz has rated The Hitchhikers Guide To The Galaxy as a 4, butJohn has already rated this book.? Liz has rated Watership Down as 1, but the rating is too low.? Liz hasn’t rated The Five People You Meet in Heaven? Liz has rated Speak as a 5. John hasnt read that book yet, so we add itto the list of recommendations.There are no more books that Liz has rated, so were done. Our final list ofrecommendations will be:speak by laurie halse andersonHere are examples of output in different situations:● If there are no books to recommend for a certain user, print the following:There are no recommendations for at the present● If there is at least one book to recommend for a certain user, print the following:Here are the list of recommendations: by by …… by Driver functionIn addition to the menu functionality used in the Homework 6 and 7, we need to add 4more options. You can find the updated displayMenu function in Hmwk8.cpp on Moodle.Menu options:1. Read book file○ Prompt the user for a file name○ Pass the file name to your readBooks function.○ After the function returns, print the total number of books in the database:Total books in the database: ○ If no books are saved to the database due to wrong file name, then printthe following message:No books saved to the database2. Read user file○ Prompt the user for a file name.○ Pass the file name to your readRatings function○ After the function returns, print the total number of users in the database:Total users in the database: ○ If no books are saved to the database due to wrong file name, then printthe following message:No users saved to the database3. Print book list○ Call your printAllBooks function.4. Find number of books user rated○ Prompt the user for a username.○ Pass the username to your getCountReadBooks function○ If the user exists in the system, print the result in the following format: rated books5. Get average rating○ Prompt the user for a title.○ Pass the title to your calcAvgRating function○ If the title exists in the database, print the result in the following format:The average rating for is Note: is a double with 2 decimal points.6. Make a new account○ Prompt the user for a username:Enter a username:○ Pass the username to your addUser function○ Based on the return value from the addUser function, you need to print amessage. If the user has successfully been added to the database, print:Welcome to the library ○ If the user was not added to the database, print: could not be added in the database7. Check Out Book○ Prompt the user for the username, the title of a book, and the new ratingEnter a username:Enter a book title:Enter a rating for the book:○ Pass the username, the title, and the new rating to your checkOutBookfunction○ Based on the return value from the checkOutBook function, you need toprint a message. If the book has successfully been read and rated, print:We hope you enjoyed your book. The rating has been updated○ If the book has not successfully been read and rated, print: could not check out 8. View Ratings○ Prompt the user for a usernameEnter a username:○ Pass the username and the title to your viewRating function9. Get recommendations○ Prompt the user for a usernameEnter a username:○ Pass the username to your getRecommendations function10.Quit转自：http://ass.3daixie.com/2018110830818367.html
