Cork Institute of Technology. Higher Certificate in Computing (ACCS) - Award. January Programming II. (Time: 3 hours)

Transcription

1 Cork Institute of Technology Higher Certificate in Computing (ACCS) - Award (NFQ Level 6) January 2006 Programming II (Time: 3 hours) Answer four questions. All Questions carry equal marks. You must answer at least one question from section A. Please use a different Answer book for each section. Examiners: Ms. M. Meagher Mr. P. Fenton Mr. R.Miller

2 Section A Q.1. a) Take a look at this class definition for the Queue ADT: const int MAX_QUEUE = 10; class Queue{ private: QueueElement items[max_queue]; int front, back, count; public: }; Queue(); bool isempty(); bool isfull(); void enqueue(queueelement newitem); QueueElement dequeue(); void dequeueall(); QueueElement peek(); Write the C++ code for each of the methods of the Queue class. (12 marks) b) Write the code for a program that generates a random sequence of digits, displays them to the user for a second or so, and then asks the user to reproduce the sequence. Use a queue to store the sequence of digits. To generate a random number use the following cope snippet; the variable nrandomnumber is assigned a random number in the range 0 to max -1: Int nrandomnumber = rand()% max ; (7 marks) c) Write the pseudocode for a program that uses a stack to evaluate if a given string has a balanced set of braces i.e. the braces in the string abc{defg{ijk}{l{mn}}op}qr are balanced, while the braces in the string abc{def}}{ghij{kl}m are not balanced. (6 marks)

3 Q. 2. a) Write a function that calculates the n th power of a specified number recursively i.e. A call to the function power(5,3) generates the answer: 125. (4 marks) b) Write a recursive function that returns the number of digits in a non-negative integer i.e. A call to the function digits(100000) returns the answer 6. (4 marks) c) Write the pseudocode for the recursive binary search algorithm, which searches for a specified integer value in an array of sorted integers. (6 marks) d) Take a look at this class definition for the Sequence ADT: class Sequence { public: Sequence(); bool isempty(); int size(); void insert(int index, SeqItemType newitem); void remove(int index); SeqItemType retrieve(int index); void display(); private: ListNode *find(int index); int length; ListNode *head; }; Write the C++ code for the following methods: void insert(int index, ListItemType newitem) void display() void remove(int index) (11 marks)

4 Section B Q3. a) Write the C++ code for the Bubblesort sorting algorithm, which when passed an array, will rearrange them in descending order. (10 Marks) b) Given the following array of values, explain in a step-by step fashion how the MergeSort algorithm would arrange the values in ascending order. Explain also how recursion is important in this algorithm. 12, 14, 5, 1, 8, 26, 4, 10, 15, 3 (11 Marks) c) Of the sorting algorithms you have studied state why some are more useful than others. Q4. a) What is the purpose of Inheritance? Explain the keyword Protected. (5 marks) b) A vehicle is a class with the following member data; Make, Model, Registration date, Colour, Number of Passengers and a Current Value. It also has the following functionality; it can be registered, it can be taxed and it can be insured, and it can sit an NCT. As well as this every vehicle can depreciate (its value is decreased by a fixed amount determined by the type of vehicle). A car is a class which is a type of vehicle. It depreciates by 10% each year. A lorry is a type of vehicle which depreciates by 15%. A lorry also has a storage capacity. Write the class definitions (.h File) and declarations (.cpp) for that scenario making proper use of inheritance, polymorphism. Write a main program which allows the user creates 5 vehicles (either cars of lorries) and store them in arrays using pointers. Demonstrate the use of polymorphism in this context, by depreciating the cost of all cars. (16 Marks) c) In the description in part (b), explain whether the Vehicle class could be made abstract, and if so, how could this be achieved?

5 Q5. a) Provide pseudocode for In-order, Post-Order and Pre-Order Traversal in binary trees. (9 Marks) b) Explain, using pseudocode, the search mechanism of a binary search tree. (6 Marks) c) Explain, using an example, what happens when a node of a binary search tree is deleted. Make reference to what occurs if this node is a leaf, has 1 child node, or has two child nodes. (10 Marks) Q.6. a) Write a function using templates, which will return the larger of 2 numbers (whether, they are ints, floats, or doubles). Explain the advantage of suing templates for classes. (7 Marks) b) Explain how the value 17 would be inserted in the following Heap. Outline the steps of the algorithm involved. Likewise, explain the steps would be performed when (9,F) would be deleted. (14 Marks) c) Explain why a friend relationship might exist? Give a C++ coded example of its use.