9618_s22_qp_32 - revisedeck

9618_s22_qp_32

A paper of Computer Science, 9618

Questions:

9

Year:

2022

Paper:

3

Variant:

2

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1

Data types can be defined using pseudocode. The data type, BuildingRecord, is defined in pseudocode as: TYPE BuildingRecord DECLARE BuildingID : INTEGER DECLARE BuildingGroup : STRING DECLARE OwnerName : STRING DECLARE BuildingAddress : STRING DECLARE DateLastSold : DATE DECLARE PriceLastSold : REAL ENDTYPE A variable, BuildingRegister, is declared in pseudocode as: DECLARE BuildingRegister : BuildingRecord Write pseudocode statements to assign: • 1067 to the BuildingID of BuildingRegister • house to the BuildingGroup of BuildingRegister The type definition for BuildingRecord is changed. The data type for BuildingGroup is changed to an enumerated type, BuildingType, with values of house, bungalow, apartment and farm. Write the type declaration for BuildingType in pseudocode. Write the new declaration for BuildingGroup in pseudocode. Write the new pseudocode statement to assign house to BuildingGroup of BuildingRegister. The program is to be rewritten using Object-Oriented Programming (OOP). The data type BuildingRecord is to be changed to a class, BuildingClass. The properties for BuildingClass are BuildingID, BuildingGroup, OwnerName, BuildingAddress, DateLastSold and PriceLastSold. All the properties are set to PRIVATE, for example: PRIVATE PriceLastSold : REAL Write the declaration in pseudocode for OwnerName as PRIVATE. Explain why the properties have been set to PRIVATE.

10. Data Types and Structures → 10.1. Data Types and Records

11. Programming → 11.1. Programming Basics

Open

2

A declarative language is used to represent the following facts about a school. 01 teaches(alan, mathematics). 02 teaches(ioana, geography). 03 teaches(nina, history). 04 teaches(alan, statistics). 06 studies(ahmed, history). 07 studies(freya, history). 08 studies(kim, history). 09 studies(freya, geography). 10 studies(hua, mathematics). 11 studies(hua, statistics). 12 studies(hua, geography). 14 tutors(alan, kim). 15 tutors(alan, hua). 16 tutors(alan, freya). 17 tutors(nina, ahmed). These clauses have the following meaning: Clause Meaning Alan teaches mathematics. Ahmed studies history. Alan is Kim’s tutor. More facts are to be included. Sam studies history and Nina is his tutor. Write the additional clauses to record these facts. Using the variable Student, the goal: studies(Student, history) returns Student = freya, ahmed, kim Write the result returned by the goal: studies(Student, geography) Student = Write the goal, using the variable X, to find all the students who have a tutor that teaches them. For example, Hua has Alan for a tutor and is also taught mathematics by Alan.

9. Algorithm Design and Problem-solving → 9.2. Algorithms

11. Programming → 11.2. Constructs

19. Computational thinking and Problem-solving → 19.1. Algorithms

Open

3

The TCP/IP protocol suite has four layers. The application layer provides user services. Identify two protocols used by this layer. Describe the use of each protocol. Protocol 1 Description Protocol 2 Description Identify two other layers of the TCP/IP protocol suite. Describe the function of each layer. Layer 1 Description Layer 2 Description

14. Communication and internet technologies → 14.1. Protocols

Open

4

The following syntax diagrams show the syntax of: • a variable • an unsigned integer • a letter • a digit • an operator • an assignment statement. variable assignment statement letter letter digit X digit unsigned integer unsigned integer Y Z operator variable variable operator variable + = – * digit The following assignment statements are invalid. State the reason in each case. X1 = Y2 – 12 Reason Z = Y12 + Z1 Reason Complete the Backus-Naur Form (BNF) for the syntax diagrams shown. has been completed for you. ::= ::= ::= X | Y | Z ::= ::= ::= The syntax of an assignment statement is changed to allow each of the variables on the right-hand side of the ‘=’ symbol to be either a variable or an unsigned integer. Draw a syntax diagram for the new syntax of the assignment statement. Write the Backus-Naur Form (BNF) for your syntax diagram.

16. System Software → 16.2. Translation Software

11. Programming → 11.1. Programming Basics

11. Programming → 11.2. Constructs

Open

5

There are four basic categories of computer architecture. Single Instruction Single Data (SISD) is one architecture. Identify the three other categories of computer architecture. Describe each category that you identify. Architecture 1 Description Architecture 2 Description Architecture 3 Description

15. Hardware and Virtual Machines → 15.1. Processors, Parallel Processing and Virtual Machines

4. Processor Fundamentals → 4.1. Central Processing Unit (CPU) Architecture

Open

6

A logic circuit has two inputs A and B, and two outputs E and F. A B E F Complete the truth table for this logic circuit. INPUT OUTPUT A B E F State the name of this logic circuit. State the purpose of each output E and F. Purpose of E Purpose of F

3. Hardware → 3.2. Logic Gates and Logic Circuits

Open

7

A digital signature is used to validate the authenticity of an electronic message. In order to produce a digital signature, a digital certificate is required. State how a digital certificate is obtained. Explain how a digital signature is produced before the message is sent. Explain how the digital signature can be checked on receipt to ensure that the message has not been altered during transmission.

17. Security → 17.1. Encryption, Encryption Protocols and Digital Certificates

Open

8

A binary search or a linear search can be used to look for a specific value in an array. Complete this pseudocode algorithm for a linear search. DECLARE MyList : ARRAY[0:9] OF INTEGER DECLARE MaxIndex : INTEGER DECLARE Index : INTEGER DECLARE Found : BOOLEAN DECLARE ValueToFind : INPUT ValueToFind Found ← FALSE Index ← 0 MaxIndex ← REPEAT IF MyList[Index] = ValueToFind THEN Found ← TRUE ENDIF Index ← UNTIL Found OR Index > MaxIndex IF Found THEN OUTPUT "Value found at position ", Index ELSE OUTPUT ENDIF State the necessary condition for a binary search. Describe how to perform a binary search. Explain how the performance of a binary search varies according to the number of values in the array. Compare the performance of the algorithms for a binary search and a linear search using Big O notation for order of time complexity.

10. Data Types and Structures → 10.2. Arrays

19. Computational thinking and Problem-solving → 19.1. Algorithms

Open

9

State the reasons for including exception handling routines when writing a program. Include an example of an exception in your answer.

20. Further Programming → 20.2. File Processing and Exception Handling

Open