Question

A static method named readMovieRatings in the ratings.FileReader class that takes and ArrayList of Movies and a String as parameters. The methods returns an ArrayList of Movies. Write tests for this method in the tests.TestClasses3 class • The input ArrayList of Movies will contain Movie objects with their title and cast populated. These Movies should not have any ratings added to them. When your program, runs, it is intended for this ArrayList to be provided by your readMovies method • The input String is the name of a file to be read. Test this method with a CSV file where each line matches the format from the movie_ratings.csv file that you can download above (ie. "title,reviewerld,rating") • The method will return an ArrayList of Movies containing all of the ratings read from the input file. If a Movie from the input ArrayList does not have any ratings in the ratings file, it should not be included in the output ArrayList. If a Movie has been rated that is not included in the input ArrayList, the rating should be ignored • Movies will have unique titles. Any movies with identical titles have been removed from the source data. Do not write tests where the input ArrayList contains multiple Movies with the same title • If the input file does not exist, the method will return an empty ArrayList • The Movies in the returned ArrayList may appear in any order. Your tests should accept any order of the returned Movies • The ratings for each Movie must be in the order in which they appear in the file. When testing the Linked List of Ratings for a Movie, you can assume that they in the same order in which they appear in the file (This will make it simpler to test the Linked List)

          A static method named readMovieRatings in the ratings.FileReader class that takes and ArrayList of Movies and a String as parameters. The methods returns an ArrayList of Movies. Write tests for this method in the tests.TestClasses3 class
• The input ArrayList of Movies will contain Movie objects with their title and cast populated. These Movies should not have any ratings added to them. When your program, runs, it is intended for this ArrayList to be provided by your readMovies method
• The input String is the name of a file to be read. Test this method with a CSV file where each line matches the format from the movie_ratings.csv file that you can download above (ie. "title,reviewerld,rating")
• The method will return an ArrayList of Movies containing all of the ratings read from the input file. If a Movie from the input ArrayList does not have any ratings in the ratings file, it should not be included in the output ArrayList. If a Movie has been rated that is not included in the input ArrayList, the rating should be ignored
• Movies will have unique titles. Any movies with identical titles have been removed from the source data. Do not write tests where the input ArrayList contains multiple Movies with the same title
• If the input file does not exist, the method will return an empty ArrayList
• The Movies in the returned ArrayList may appear in any order. Your tests should accept any order of the returned Movies
• The ratings for each Movie must be in the order in which they appear in the file. When testing the Linked List of Ratings for a Movie, you can assume that they in the same order in which they appear in the file (This will make it simpler to test the Linked List)

A static method named readMovieRatings in the ratings.FileReader class that takes and ArrayList of Movies and a String as parameters. The methods returns an ArrayList of Movies. Write tests for this method in the tests.TestClasses3 class
• The input ArrayList of Movies will contain Movie objects with their title and cast populated. These Movies should not have any ratings added to them. When your program, runs, it is intended for this ArrayList to be provided by your readMovies method
• The input String is the name of a file to be read. Test this method with a CSV file where each line matches the format from the movieratings.csv file that you can download above (ie. "title,reviewerld,rating")
• The method will return an ArrayList of Movies containing all of the ratings read from the input file. If a Movie from the input ArrayList does not have any ratings in the ratings file, it should not be included in the output ArrayList. If a Movie has been rated that is not included in the input ArrayList, the rating should be ignored
• Movies will have unique titles. Any movies with identical titles have been removed from the source data. Do not write tests where the input ArrayList contains multiple Movies with the same title
• If the input file does not exist, the method will return an empty ArrayList
• The Movies in the returned ArrayList may appear in any order. Your tests should accept any order of the returned Movies
• The ratings for each Movie must be in the order in which they appear in the file. When testing the Linked List of Ratings for a Movie, you can assume that they in the same order in which they appear in the file (This will make it simpler to test the Linked List)

Added by Sarah M.

Program #6 Binary Search Trees (Please write in JAVA!) Objectives Write and use a linked implementation of a binary search tree. Problem Description In this assignment, you will practice solving a problem using a binary search tree. You will implement a Java application that could be used in a restaurant. You are asked to implement four classes: MenuItem, BSTNode, BST and Driver. Each of these classes is described below. Classes The method names, parameters and return types must match the specification exactly. You may add other methods if you wish. MenuItem Class The MenuItem class represents one item ordered from a menu. The MenuItem has three instance variables: name (of type String), qty (of type int) and price (of type double). Implement the following methods for the MenuItem class: A constructor to initialize all instance variables. A value for each instance variable will be passed as a parameter to the constructor. The parameters must be in the order (name, qty and price). The instance variable name will be used as the search key and as the instance variable that will determine the order in which the items are stored in the binary search tree. Getters for all instance variables. Setter methods for each instance variable. equals(): Implement the equals() method for your MenuItem where two MenuItems are considered equal when they have the same search key (name). Other instance variables must be ignored. Use the standard signature for the equals() method. Note that, the equality of String attributes should be case insensitive. For example, “MATH”, “math” and “Math” match each other. In order to compare strings in Java use the String's equalsIgnoreCase() method. For example, the following code should print true: String str1 = "Hello"; String str2 = "hello"; System.out.println(str1.equalsIgnoreCase(str2)); toString(): a method that returns a nicely formatted string description of the item. All items should be separated by tabs (use " ") and the entire MenuItem should be displayed on one line. In addition to name, price and qty, calculate the total value of the MenuItem (price * qty) and add it to the end of the string. Rice $1.50 3 $4.50 Use the NumberFormat or DecimalFormat class to display prices with exactly two digits following the decimal place. Implement the Comparable interface and the compareTo() method for MenuItem. compareTo() returns a negative number when the invoking object's search key (name) is less than the parameter's search key 0 when the two search keys (names) are equal a positive number when the invoking object's search key (name) is greater than the parameter's search key For example, "Ant".compareTo("bat") will return a negative number. Note that the comparison of String attributes should be case insensitive. For example, “MATH”, “math” and “Math” match each other. Base the comparison only on the search key. All other instance variables must be ignored. BSTNode Class Create a BSTNode class. You must create your own BSTNode class and you may not use any node classes from the Java library. The BSTNode instance variables consist of data and two links, left and right. The data instance variable must be of type MenuItem. The instance variables must be private. Implement a constructor with parameters data, left and right, in that order. Implement getters and setters for all instance variables. Your Tree class must be separate from your BSTNode class. You may implement a generic BSTNode class if you like. BST Class The MenuItems data must be stored in a recursive binary search tree data structure. This means the data is stored in order according to the binary search tree principles. You must create your own binary search tree class (separate from the BSTNode class) and implement the recursive methods you need. You must create your own BST class and you may not use any tree classes from the Java library. Be sure to implement encapsulation by having a clean separation between the node and binary search tree classes. Do this by making the instance variables private in both classes and by putting methods that manipulate more than one node in the BST class. Use a linked implementation. The BST class will have one private instance variable, root, which will hold a reference to the topmost node in the tree. The BST class methods must include these recursive methods: A no-arguments constructor that instantiates an empty binary search tree. void insert(MenuItem mi): a method that takes one input parameter, a MenuItem, and adds it to the binary search tree in the proper spot, preserving the binary search tree property. If the MenuItem is already in the tree, insert() will not add a new item to the tree but rather will increment the qty of the existing item by the new qty. If the MenuItem is not already in the tree, the method inserts the MenuItem in its correct position void preorder() – traverses the tree in pre-order (based on the search key) and prints the contents of each Node void postorder() - traverses the tree in post-order (based on the search key) and prints the contents of each Node void inorder() - traverses the tree in post-order (based on the search key) and prints the contents of each Node size(): a method that returns the number of nodes in the tree int depth(): returns the height (depth) of the tree. Note: An empty tree has a height of -1. A tree with one node has height of 0. getTotalQty(): an integer method that sums and returns the quantities of all MenuItems in the Tree MenuItem search(String name) – traverses the tree and returns a reference to a MenuItem with a search key (name) that matches the parameter. Returns null if not found. getTotalBeforeTax(): a method that calculates and returns the total value of all items in the tree. Remember to multiply the price by the quantity to get the total for each item. getTax(): a method with one parameter, taxRate (a double). getTax() calculates and returns a double representing the tax to be paid on the order getTip(): a method with one parameter, percentage (a double). getTip() calculates and returns a double representing the tip to be paid on the order's total before tax. toString(): a method that returns a string representation of all the MenuItems in the tree. The items will be displayed in alphabetical order. The String includes the following: a restaurant name and some header lines details of all the MenuItems, one per line the total of all the items in the tree before tax and tip been added the amount of tax to be added (use a fixed rate of 8%) the amount of tip to be added (use a fixed rate of 20%) the total after tax and tip have been added Sample of String returned from toString(): Downtown Cafe --------------------------------------------------- Item Price Qty Total --------------------------------------------------- Injera $2.50 1 $2.50 Rice $1.50 3 $4.50 Sambusa $5.80 4 $23.20 Sushi $8.25 2 $16.50 --------------------------------------------------- Total: $46.70 Tax: $3.74 Tip: $9.34 --------------------------------------------------- Grand total: $59.78 You are required to use the approach outlined in class with a public method with no arguments (one argument in the case of insert(), search(), getTax() and getTip()) and a private helper method. You may *not* directly access the root of the tree from the driver. You may *not* implement a public getRoot() method. With the exception of inorder(), preorder() and postorder(), the Tree class should not contain any print statements. All printing occurs in the Driver. Driver Use the Driver class to demonstrate that the BST class and its methods work properly. Create one or two BST trees. Add 20 to 25 MenuItems to the trees. Change the order of insertion to test different tree topologies. Do not add the items in alphabetical order or your tree will degenerate to a linked list. Call all the BST methods and display the results. Be sure to test the case where the MenuItem is already been in the tree (insert() causes the existing item's quantity to be changed). Print both orders in a nicely formatted output.

Sri K.

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