IB Computer Science Topic D.4 Advanced Program…

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IB Computer Science Topic D.4 Advanced Program… | RevisionDojo

Question

HLPaper 2

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Consider the following recursive method.

public void recursionEx(int x)
{
    if(x != 0)
    {
        System.out.println(x);
        recursionEx(x - 1);
        System.out.println(x);
    }
}

(a)

two essential features of a recursive algorithm.

A recursive algorithm must have a base case (terminating condition) that stops the recursion
A recursive algorithm must have a recursive case where the algorithm calls itself with a simpler/smaller version of the problem

[2]

(b)

Trace the execution of the method call recursionEx(3) and complete the table to show the sequence of calls and the values printed to the console.

(c)

what would happen if the method was called by recursionEx(-3).

public static void recursionEx(int n) {
    if (n < 0) {
        System.out.println("Done");
    } else {
        System.out.println(n);
        recursionEx(n - 1);
        System.out.println(n);
    }
}

Show the output that would be produced when the method is called with recursionEx(-3).

[3]

(d)

three features which should be included in either program code or UML diagrams to help programmers understand and modify programs in the future.

[3 marks]

[3]

HLPaper 2

The array line in POSline is now replaced by a singly linked list of CartNode objects. The class CartNode has been defined as follows.

public class CartNode
{
private Cart myCart;
private CartNode next;
public CartNode(Cart aCart)
{
this.myCart = aCart;
this.next = null;
}
public Cart getCart(){ return this.myCart; }
public CartNode getNext(){ return this.next; }
public void setNext(CartNode nextNode)
{
this.next = nextNode;
}
}

The class POSlist has been implemented with the standard list methods addLast and removeFirst that act on list.

A method leaveList(int n) is required in the class POSlist, similar to the method leaveLine(int n) that was added to the class POSline.

(a)

the term .

HLPaper 2

A different airport has two runways for arriving flights. Two objects of the LinkedList class, named runway1 and runway2, are associated with these two runways.

Arriving flights are added to a list depending on the runway they are assigned to.

Both linked lists contain Arrival objects, corresponding to arriving flights, and are sorted by ETA.

The following diagram represents runway1.

Consider the following method.

void process(LinkedList myList, int i)
{ if (i < myList.size())
{ process(myList, i + 1);
System.out.println(myList.get(i).getETA());
}
}

(a)

an advantage of using a library.

[2]

SLPaper 2

A software engineer is developing an inventory management system for a warehouse. To find specific items quickly, the engineer is implementing a search module. The initial version of the search function is shown below:

public int linearSearch(String[] inventory, String target)
{
    int index = -1;
    for (int i = 0; i < inventory.length; i++) {
        if (inventory[i].equals(target)) {
            index = i;
        }
    }
    return index;
}

The warehouse currently stores thousands of items. The engineer is considering ways to optimize the search process and ensure the software is easy to maintain for future developers who might work on the system.

(a)

one advantage of using modular sub-programs (methods or functions) in a large software project.

[2]

(b)

HLPaper 2

The organizing school arranges for visiting students to stay with a host family. The information about each of the visiting students is stored in a file. The student records are sorted by name. Some of the other variables included are school, gender, age and host family name, as shown in the UML diagram below.

A program needs to be written to match visiting students with host families. The matching process requires data to be manipulated extensively (adding, editing, deleting). The file will be read into RAM.

This program will be used for different events with different numbers of visitors. Therefore, it will be implemented using a dynamic data structure.

It has been decided to use a single linked list named guests to store and manipulate the Visitor objects.

Consider the following diagram which represents the list guests.

The following recursive method has been written to act on the list guests.

public void recursive(int k, char a)
{
if (k == guests.size())
{
output ('no such record');
}
else {
Visitor current = guests.get(k);
if ((current.getGender() == a) && (current.getAge() > 15))
{ current.getName(); } { recursive(k + 1,a); } } }

Practice IB Computer Science (CS) Topic D.4 Advanced Program Development with authentic exam-style questions for both SL and HL students. This question bank focuses on the exact syllabus content for D.4 Advanced Program Development and mirrors Paper 1, 2, 3 style where relevant.

Get instant solutions, detailed explanations, and build confidence with questions aligned to IB examiner expectations.

recursionEx(3)	3	3
recursionEx(2)	2	2
recursionEx(1)	1	1
recursionEx(0)	0
return to recursionEx(1)	1	1
return to recursionEx(2)	2	2
return to recursionEx(3)	3	3

IB Computer Science D.4 Advanced Program Development Questionbank

IB Computer Science D.4 Advanced Program Development Questionbank

IB Computer Science D.4 Advanced Program Development Questionbank

IB Computer Science D.4 Advanced Program Development Questionbank

IB Computer Science (CS) Topic D.4 Advanced Program Development Questionbank