CMPS 200 Problems Extra Problems, Fall 2016

Music Collection Class CD Implement the CD class which defines the properties of objects that we will use later to represent CDs. The table below gives the UML description of the CD class. Recall that, in UML, the following notation: + setTitle(title : String) : void indicates that setTitle is a public (- means private) method that accepts a String parameter called title and returns nothing (void). CD - title : String - artist : String - cost : double - tracks : int + CD (title : String, artist : String, cost : double, tracks : int) + setTitle(title : String) : void + setArtist(artist : String) : void + setCost(cost : double) : void + setTracks(tracks : int) : void + getTitle() : String + getArtist() : String + getCost() : double + getTracks() : int + equals(cd: CD) : boolean + compareTo(cd : CD) : int + toString() : String The CD class defines four instance variables. It has one constructor that initializes the instance variables using the passed parameters. It also defines appropriate setters and getters as noted in the UML representation above. Note that your code must observe the naming convention specified above. For example, in the setTitle method, the name of the parameter must be title. The CD class defines a compareTo method that compares two CDs according to their titles first and their artists next. It returns a negative number (e.g., –1) if the current CD has a (title, artist) pair that is smaller than that of the passed CD object, a positive number (e.g., +1) if it is larger, and 0 otherwise. It has an equals method that also only uses the title and artist fields to decide if two CD objects have the same content. Finally the CD class defines a toString method that generates a printable representation of the current CD’s information in a nice format (all information on one line—check the sample output below). The driver class CDDriver is provided to you and can be used to test your CD class. Sample Run C:> java CDDriver CD1: $14.95 10 Storm Front Billy Joel CD2: $17.95 33 Soundtrack Les Miserables CD3: $19.95 22 Soundtrack Chicago CD4: $19.95 24 Soundtrack Moulin Rouge CD1 >= CD2 CD2 >= CD3 CD3 < CD4 Classes CDCollection & CDCollDriver Implement the CDCollection class described in the UML diagram below. CDCollection - collection : CD[] // initial size is 2 - count : int - totalCost : double + CDCollection() + CDCollection(size: int) + add(title : String, artist : String, cost : double, tracks : int) : void + add(cd : CD) : void + toString() : String - increaseSize() : void An instance of the CDCollection class contains an array of CD objects to store the CDs in the collection. It maintains a count of the CDs in the collection (in the count field) and their combined value (in the totalCost field). It uses the CD count to decide when to create a larger array if too many CDs are added to the collection. • The collection array is instantiated in two different ways: (1) using the CDCollection no- arg constructor which initializes the collection array to have a size of 2 or (2) using the CDCollection one argument constructor which initializes the collection array and sets its size to the passed value. • Every time a CD is added to the collection (using one of the add methods), a new CD object is created and a reference to it is stored in the first available slot in the collection array. Each time a CD is added to the collection, we check to see if we have reached the current capacity of the collection array. If the current capacity has been reached, the private increaseSize method is invoked, which doubles the size of the collection array. The toString method of the CDCollection class returns an entire report summarizing the collection. The report should be created using implicit calls to the toString method of each CD object stored in the collection. For example, in the CDCollDriver driver class (which is provided to you), when “System.out.println (music);” is called for the first time, the following output should be displayed: Sample Run C:> java CDCollDriver My CD Collection Number of CDs: 5 Total value: $80.74 Average cost: $16.15 CD List: $14.95 10 Storm Front Billy Joel $14.95 16 Come On Over Shania Twain $17.95 33 Soundtrack Les Miserables $13.90 11 Graceland Paul Simon $18.99 18 Ella in Rome Ella Fitzgerald Classes CDUniqCollection & Tunes Implement the CDUniqCollection class described in the UML diagram below. CDUniqCollection - collection : CD[] // initial size is 2 - count : int - totalCost : double + CDUniqCollection() + CDUniqCollection(size: int) + add(title : String, artist : String, cost : double, tracks : int) : void + add(cd : CD) : void + sort() : void + remove(title : String, artist : String) : CD + toString() : String - findIndex(title : String, artist : String) : int - increaseSize() : void The CDUniqCollection class is very similar to the CDCollection class and differs from it as follows: • It does not add a CD to the collection if it already has one with the same title and artist. The private method findIndex can be used for this purpose. • It has a private method findIndex that can be used to check if the CD already exists in the collection. It accepts as parameters a CD title and artist and then searches the collection array looking for a CD with the same title and artist. If such a CD were to exist, it returns the index of that CD in the collection array, otherwise it returns –1. • The sort method of the CDCollection class sorts all the CDs in the collection according to their (title, artist) fields in ascending order. • The remove method of the CDCollection class accepts the title and author of a certain CD, removes the corresponding CD from the collection, and returns the removed CD. Before removing the CD, you need to make sure that the CD exists in the collection. The private method findIndex can be used for this purpose (similar to what was described in the add method). Note that when you remove a CD from the collection array, all CDs that are to its right must be shifted one place to left. Also, the current size of the collection array must be decreased by 1. The Tunes driver class is provided to you. Its sample run is shown below. Sample Run C:> java Tunes My Unique CD Collection Number of CDs: 4 Total value: $61.75 Average cost: $15.44 CD List: $14.95 16 Come On Over Shania Twain $13.90 11 Graceland Paul Simon $17.95 33 Soundtrack Les Miserables $14.95 10 Storm Front Billy Joel Remove 1 CD: $14.95 10 Storm Front Billy Joel Add 3 CDs My Unique CD Collection Number of CDs: 6 Total value: $98.54 Average cost: $16.42 CD List: $14.95 16 Come On Over Shania Twain $13.90 11 Graceland Paul Simon $17.95 33 Soundtrack Les Miserables $15.80 13 Cedarland Walid Keirouz $19.99 26 Double Live Garth Brooks $15.95 13 Greatest Hits Wassim El-Hajj Remove: $15.80 13 Cedarland Walid Keirouz My Unique CD Collection Number of CDs: 5 Total value: $82.74 Average cost: $16.55 CD List: $14.95 16 Come On Over Shania Twain $19.99 26 Double Live Garth Brooks $13.90 11 Graceland Paul Simon $15.95 13 Greatest Hits Wassim El-Hajj $17.95 33 Soundtrack Les Miserables