9618_s21_qp_32
A paper of Computer Science, 9618
Questions:
9
Year:
2021
Paper:
3
Variant:
2
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1
Real numbers are stored in a computer system using floating-point representation with: • 10 bits for the mantissa • 6 bits for the exponent • Two’s complement form for both the mantissa and the exponent. Calculate the normalised floating-point representation of –7.25 in this system. Show your working. Mantissa Exponent Working Calculate the denary value of the given binary floating-point number. Show your working. Mantissa Exponent Working Answer The given binary floating-point number is not normalised. Normalise the floating-point number. Show your working. Mantissa Exponent Mantissa Exponent Working The denary number 513 cannot be stored accurately as a normalised floating-point number in this computer system. Explain the reason for this. Describe an alteration to the way floating-point numbers are stored to enable this number to be stored accurately using the same total number of bits.
13. Data Representation  →  13.3. Floating-point numbers, representation and manipulation
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2
Describe the purpose of a user-defined data type. Define, using pseudocode, the following enumerated data types: SchoolDay to hold data about the days students are usually in school. WeekEnd to hold data about the days that are not school days. Define, using pseudocode, the composite data type ClubMeet. This will hold data about club members that includes: • first name and last name • the two days they attend: ○ one on a school day ○ one not on a school day. Use the enumerated types you created in part .
10. Data Types and Structures  →  10.1. Data Types and Records
13. Data Representation  →  13.1. User-defined data types
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3
Draw one line to connect each Operating System (OS) term to the most appropriate description about it. OS term Description Using secondary storage to simulate additional main memory Managing the processes running on the CPU Managing the execution of many programs that appear to run at the same time Locating non-contiguous blocks of data and relocating them Transferring control to another routine when a service is required Reading/writing same-size blocks of data from/to secondary storage when required Multi-tasking Paging Interrupt handling Scheduling Virtual memory Explain how an interpreter executes a program without producing a complete translated version of it.
16. System Software  →  16.1. Purposes of an Operating System (OS)
16. System Software  →  16.2. Translation Software
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4
Explain why Reverse Polish Notation (RPN) is used to carry out the evaluation of expressions. Identify, with reasons, a data structure that could be used to evaluate an expression in RPN. Write the infix expression in RPN. (a – b) * (a + c) / 7 Write the RPN expression as an infix expression. a b / 4 * a b + - Evaluate the RPN expression: a b + c d / / where a = 17, b = 3, c = 48 and d = 12. Show your working.
16. System Software  →  16.2. Translation Software
11. Programming  →  11.1. Programming Basics
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5
Calculate the shortest distance between the base and each of the other towns in the diagram using Dijkstra’s algorithm. Show your working and write your answers in the table provided. Base Town 1 Town 3 Town 5 Town 4 Town 2 Town 6 Working Answers Town 1 Town 2 Town 3 Town 4 Town 5 Town 6 Explain the use of graphs to aid Artificial Intelligence (A.
18. Artificial Intelligence (AI)  →  18.1. Artificial Intelligence (AI)
19. Computational thinking and Problem-solving  →  19.1. Algorithms
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8
State two factors that may affect the performance of a sorting algorithm. The given algorithm is a simple bubble sort that arranges a set of scores stored in a one- dimensional array into descending order, and orders the corresponding students’ names stored into a two-dimensional array in the same order as the scores. All the arrays are indexed from 1. The contents of both arrays after sorting are shown. Score Name Smithfield Tom Johnson Jane … … Peters Jade Allen John YearSize ← 249 Flag ← TRUE WHILE Flag = TRUE Flag ← FALSE FOR Student ← 1 TO YearSize - 1 IF Score[Student] < Score[Student + 1] THEN Temp1 ← Score[Student] Temp2 ← Name[Student,1] Temp3 ← Name[Student,2] Score[Student] ← Score[Student + 1] Name[Student,1] ← Name[Student + 1,1] Name[Student,2] ← Name[Student + 1,2] Score[Student + 1] ← Temp1 Name[Student + 1,1] ← Temp2 Name[Student + 1,2] ← Temp3 Flag ← TRUE ENDIF NEXT Student ENDWHILE
19. Computational thinking and Problem-solving  →  19.1. Algorithms
10. Data Types and Structures  →  10.2. Arrays
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9
Describe what is meant by an imperative programming language. Describe what is meant by a declarative programming language. Identify the programming paradigm for each of these program code examples. Program code example Programming paradigm male. female. parent(john, ethel). FOR Counter = 1 TO 20 X = X * Counter NEXT Counter Start: LDD Counter INC ACC STO Counter public class Vehicle { private speed; public Vehicle() { speed = 0; } }
20. Further Programming  →  20.1. Programming Paradigms
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