COMP 1006/1406: Assignment # 3 Due Monday July 27, 2015, 12:00 Noon Total Marks: 60

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1 COMP 1006/1406: Assignment # 3 Due Monday July 27, 2015, 12:00 Noon Total Marks: 60 Submission Instructions Put all of your written answers in a PDF. Here are some options for how to create a PDF: You can save a PDF directly from Microsoft Word (instructions HERE) and Google Docs. On a Mac, you can save anything as a PDF from the print dialog (instructions HERE). Put your work for each coding question into a separate code::blocks project, naming the project/folder according to the question (e.g. Question1). You will submit the whole folder that code::blocks creates. Create a zip file of all your files and folders: On Windows, select the files you want to include, right click, choose Send to then Compressed (zipped) folder On a Mac, select the files you want to include, right click, and choose Compress X Items Name your zip file FirstnameLastname Assignment#.zip (where # is the assignment number) Failure to follow submission instructions can result in a loss of up 2 marks. 1

2 Written Questions Question 1 (3 marks) Explain in your own words what the difference(s) between a class definition and an object instance are, regardless of the programming language [2 marks]. After making this distinction, use an analogy to illustrate the difference (dont reuse any that were presented in class or textbook) [1 marks]. Question 2 (3 marks) Explain, in your own words, what function overloading is [1 marks]. Give an example of when you would want to do this (make sure to give at least two function prototype to illustrate your example) [2 marks]. Question 3 (2 marks) Explain what happens in memory when you make an attribute of a class static [1 mark] and give an example of a useful scenario (other than tracking the ID of a class) where you might want to have a static attribute [1 mark]. Coding Questions Coding Style Insufficient comments Inconsistent formatting (curly braces and tabs) Insufficient use of variables and/or poor variable names Insufficient use of methods and/or poor method names Insufficient use of classes and/or poor class names 2

3 Question 4 (6 marks) Translate the following C++ code into Java code. Put your new code into a folder called Question4. You will get full marks for correctly understanding the differences between the two languages and making the code work again in Java. #include <iostream> #include <string> using namespace std; struct car string modelname; int year; int kmdriven; ; void increasemilage(car &cartoupdate, int amount) cartoupdate.kmdriven += amount; int averagedistancedriven(car cars[], int size) int average = 0; for (int i = 0; i < size; i++) average += cars[i].kmdriven; return average/size; int main() car cars[4] = "corvette", 1996, , "dodge ram", 2015, 4000, "pinto", 1978, , "jeep", 2010, 91000, ; increasemilage(cars[1], ); cout << "The average distance driven is: "; cout << averagedistancedriven(cars, 4) << "km\n"; return 0; 3

4 Question 5 (6 marks) Translate the following Java code into C++ code. Put your new code into a code::blocks project called Question5. You will get full marks for correctly understanding the differences between the two languages and making the code work again in C++. public class Question5 public static int countoccurrences(int[] data, int item) int count = 0; for (int i = 0; i < data.length; i++) if (data[i] == item) count++; return count; public static void main(string[] args) int[] data = new int[30]; for (int i = 0; i < 10; i++) data[i] = i*2; for (int i = 10; i < 25; i++) data[i] = i-6; for (int i = 25; i < 30; i++) data[i] = (i*i) - (5 * i); for (int i = 0; i < data.length; i++) System.out.print(data[i] + " "); System.out.println(); System.out.println(countOccurrences(data, 16)); System.out.println(countOccurrences(data, 8)); System.out.println(countOccurrences(data, 594)); 4

5 Question 6 (25 marks) We will create Java classes for a bicycle. The bicycle is capable of having accessories on the front and back and is capable of holding a variety of objects in its basket. Define a class called Accessory. These will be accessories you can add to the front or back of the bicycle. It should have a type (String) and a colour (String). Provide a constructor (which allows for these attributes to be set) [2 marks] as well as the following function: public String tostring() which converts the accessory to an appropriate String. For example if the type is light and the colour is red, then the method could return a red light [1 mark]. Define a class called CarryableItem. These will be items that can be carried in the bicycle s basket. It should have a name (stored as a string) and a weight (stored as a double). Provide a constructor (which allows each attribute to be set)[2 marks] as well as the following function: public String tostring() which converts the item to an appropriate String. For example if the name is book and the weight is 1.2, then the method could return a 1.2 kg book [1 mark]. Define a class called Bicycle. It should have a colour (stored as a String), a number of speeds (stored as an int). It should also have references to a front accessory and back accessory and references the items being carried in its basket. The basket can hold a a maximum of 3 items. Provide a constructor which allows the colour and number of speeds to be set, sets the accessories to null and allocates an array of items of size 3, each place in the array set to null [2 marks]. The class will also have the following functions: public String tostring() which converts the entrie bicycle to an appropriate String [3 marks]. For example, if the colour of the bicycle blue, it is a 10 speed with a front accessory of type bell with the colour black, a back accessory of type light and colour red carrying a 2 kg grocery bag and a 2.6 kg bowling ball in the basket, then the method could return: This is a red 10-speed bicycle, with a black bell in the front, a red light in the back, a 2 kg grocery bag and a 2.6 kg bowling ball in the basket. Note: it is possible that the Bicycle doesn t have any accessories or has nothing in the basket. For example, if you have a newly created red 10-speed bicycle with an empty bicycle and no accessories, this method could return: This is a red 10-speed bicycle with nothing in the front, nothing in the back and nothing in the basket. You need to account for all of these scenarios in your method to produce a suitable string [4 marks]. public void carryitem(carryableitem item) which adds item to the basket if there are less than three items currently in the basket, otherwise it does nothing [2 marks]. public void emptybasket() removes all CarryableItems from the bicycle s basket, if there are any [2 marks]. public void addfrontaccessory(accessory a) which places the given accessory on the front of the bicycle (replacing the current accessory, if any) [1 mark]. public void addbackaccessory(accessory a) which places the given accessory on the back of the bicycle (replacing the current accessory, if any) [1 mark]. 5

6 public boolean issafe() which will determine if the current bicycle is safe. A safe bicycle has a front accessory with the type bell, a back accessory with the type light and a basket with a total weight less than 5 [3 marks]. Create a class called TestClass that tests the code written above. Your testing should convince the TAs that your code works, so be sure to call every method at least once [4 marks]. Question 7 (15 marks) Using Java, update the singly-linked list we saw in class to be a doubly-linked list (described in Part A). You must start with the actual code presented in class, which is also available in culearn. For the purposes of this question, the linked list will hold objects of type String (this means that you will change datas type from ReadThis to String). In the node class, add a reference to the previous node, stored in the attribute prev [1 mark]. Ensure that all of the lists methods for addition and removal of nodes update the prev reference appropriately. These methods include adding and removing a node from the beginning, the end, and after some other node [6 marks]. Do not change the names of the methods from the original code. Add a method to the list node called public String concatenate() that concatenates all of the Strings of the list, in order, and returns the result [3 marks]. Add a new method to the list node called public ListNode reverse() that reverses the list in-place (i.e., without creating a new copy of the list) starting at the calling node, and returns the new head. For example, a list that was previously A B C D will become D C B A [3 marks]. Create a class called TestClass that tests the code written above. Your testing should convince the TAs that your code works, so be sure to call every method at least once [2 mark]. 6