Cambridge IGCSE Computer Science (9-1) 0984 — 2022 May/June Paper 2 · Variant 2

This document has 12 pages. [Turn over Cambridge IGCSE™(9–1) DC (LK) 311521 © UCLES 2022 * 8 0 5 0 9 3 4 5 3 8 * COMPUTER SCIENCE 0984/22 Paper 2 Problem-solving and Programming May/June 2022 1 hour 45 minutes You must answer on the question paper. No additional materials are needed. INSTRUCTIONS ● Answer all questions. ● Do not attempt Tasks 1, 2 and 3 in the copy of the pre-release material on page 2; these are for information only. ● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs. ● Write your name, centre number and candidate number in the boxes at the top of the page. ● Write your answer to each question in the space provided. ● Do not use an erasable pen or correction fluid. ● Do not write on any bar codes. ● Calculators must not be used in this paper. INFORMATION ● The total mark for this paper is 50. ● The number of marks for each question or part question is shown in brackets [ ]. ● No marks will be awarded for using brand names of software packages or hardware.

2 0984/22/M/J/22 © UCLES 2022 Section A You are advised to spend no longer than 40 minutes answering this section. Here is a copy of the pre-release material. DO NOT attempt Tasks 1, 2 and 3 now. Use the pre-release material and your experience from attempting the following tasks before the examination to answer Question 1. Pre-release material A program is needed to allow a Wildlife Park to sell tickets. A booking consists of one or more tickets for the same day(s) and can be made up to a week in advance. A booking can be made for a visit of one day or two consecutive days. A booking can have extra attractions included. A booking will be valid for the day(s) chosen only. Ticket type Cost for one day Cost for two days one adult $20.00 $30.00 one child (an adult may bring up to two children) $12.00 $18.00 one senior $16.00 $24.00 family ticket (up to two adults or seniors, and three children) $60.00 $90.00 groups of six people or more, price per person $15.00 $22.50 Extra attraction Cost per person lion feeding $2.50 penguin feeding $2.00 evening barbecue (two-day tickets only) $5.00 Write and test a program or programs for the Wildlife Park: • Your program or programs must include appropriate prompts for the entry of data. Data must be validated on entry. • All outputs, including error messages, need to be set out clearly and understandably. • All variables, constants and other identifiers must have meaningful names. You will need to complete these three tasks. Each task must be fully tested. Task 1 – displaying the ticket options and the extra attractions available Set up your program to: • display the options, attractions and prices for one-day tickets • display the options, attractions and prices for two-day tickets • show the days available for booking; assume that there are tickets available for any valid day. Task 2 – process a booking Extend your program for Task 1 to: • input the tickets and extra attractions required, then calculate the total cost of the booking • allocate a unique booking number • display the booking details, including the total cost and the unique booking number • repeat as required. Task 3 – ensuring each booking is the best value Check that the total for each booking gives the best value and offer an alternative if this is not the case. For example, buying two family tickets is better than a group ticket for a group of 10 that includes four adults and six children.

3 0984/22/M/J/22 © UCLES 2022 [Turn over 1 All variables, constants and other identifiers must have meaningful names. (a) (i) Identify one constant that you could have used for Task 1. Give the value and use of the constant. Constant … Value … Use … … [3] (ii) Identify one variable that you could have used for Task 2. Give the data type and use of the variable. Variable … Data type … Use … … [3] (b) Explain how your program showed the days available for booking in Task 1. … … … … … … [3] (c) Explain how your program made sure that each booking number allocated in Task 2 was unique. … … … … [2]

4 0984/22/M/J/22 © UCLES 2022 (d) Write an algorithm for the part of Task 2 that inputs the tickets and extra attractions required then calculates the total cost of the booking. Assume that the booking is for a single day. Use pseudocode, programming statements or a flowchart. … … … … … … … … … … … … … … … … … … … … … … … … …

5 0984/22/M/J/22 © UCLES 2022 [Turn over … … … … … … … … … … … … … … … … … … … … … … … … … … … [6]

6 0984/22/M/J/22 © UCLES 2022 (e) Explain how your program decides when a family ticket is better value in Task 3. Any programming statements that you include in your answer must be fully explained. … … … … … … … … … … [3]

7 0984/22/M/J/22 © UCLES 2022 [Turn over Section B starts on page 8

8 0984/22/M/J/22 © UCLES 2022 Section B 2 An algorithm allows a user to input their password and checks that there are at least eight characters in the password. Then, the user is asked to re-input the password to check that both inputs are the same. The user is allowed three attempts at inputting a password of the correct length and a matching pair of passwords. The pre-defined function LEN(X) returns the number of characters in the string, X 01 Attempt ← 0 02 REPEAT 03 PassCheck ← TRUE 04 OUTPUT "Please enter your password " 05 INPUT Password 06 IF LEN(Password) < 8 07 THEN 08 PassCheck ← TRUE 09 ELSE 10 OUTPUT "Please re-enter your password " 11 INPUT Password2 12 IF Password <> Password 13 THEN 14 PassCheck ← FALSE 15 ENDIF 16 ENDIF 17 Attempt ← Attempt + 1 18 UNTIL PassCheck OR Attempt <> 3 19 IF PassCheck 20 THEN 21 OUTPUT "Password success" 22 ELSE 23 OUTPUT "Password fail" 24 ENDIF (a) Identify the three errors in the pseudocode and suggest a correction to remove each error. Error 1 … Correction … Error 2 … Correction … Error 3 … Correction … [3]

9 0984/22/M/J/22 © UCLES 2022 [Turn over (b) The algorithm includes two types of check on the data input. Identify and describe each type of check. Type of check 1 … Description … … Type of check 2 … Description … … [4] (c) Give two sets of test data for this algorithm and a reason for choosing each set. Each set of test data and its reason must be different. Set 1 … Reason … … Set 2 … Reason … … [4] 3 (a) Describe a one-dimensional array. Include an example of an array declaration. … … … … … … [3] (b) Explain how indexing could be used to search for a value stored in a one-dimensional array. … … … … [2]

10 0984/22/M/J/22 © UCLES 2022 4 This algorithm checks the temperature of hot food being served to customers. START Counter 0 Counter Counter + 1 Error ((Hot + Cold) / Counter) * 100 Hot 0 Cold 0 Serve 0 Serve Serve + 1 INPUT Temp OUTPUT Error OUTPUT "Too Cold" OUTPUT "Too Hot" Is Temp = –1? Is Temp > 86? Is Temp < 63? END Hot Hot + 1 Cold Cold + 1 Yes No No No Yes Yes

11 0984/22/M/J/22 © UCLES 2022 [Turn over (a) Complete the trace table for the algorithm using this input data: 75, 78, 84, 87, 91, 80, 75, 70, 65, 62, –1, 20 Counter Hot Cold Serve Temp Error OUTPUT [7] (b) State how the final output from the algorithm could be improved. … … [1] (c) Identify the process in the algorithm that is not required. … … [1]

12 0984/22/M/J/22 © UCLES 2022 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. 5 A database table, NURSE, is used to keep a record of disposable items worn by veterinary nurses. This is part of the table: ItemNumber Description SingleUse Uses StockLevel ReorderLevel DIG1 Glove (pair) Y 1 500 800 DIA1 Apron Y 1 700 800 DIM5 Hair net Y 1 650 500 DIA2 Apron N 5 25 100 DIS4 Suit N 3 70 50 DIV9 Shoe cover (pair) Y 1 400 250 (a) Complete this query-by-example grid to display only the item number and the description of single use items, where the stock level is below the reorder level. Field: Table: Sort: Show: Criteria: or: [4] (b) Give a reason why the field SingleUse is not required in the table NURSE. … … [1]

This document consists of 12 printed pages. © UCLES 2022 [Turn over Cambridge IGCSE™ (9–1) COMPUTER SCIENCE 0984/22 Paper 2 Problem-solving and Programming May/June 2022 MARK SCHEME Maximum Mark: 50 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the May/June 2022 series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components.

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 2 of 12 Generic Marking Principles These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these marking principles. GENERIC MARKING PRINCIPLE 1: Marks must be awarded in line with:  the specific content of the mark scheme or the generic level descriptors for the question  the specific skills defined in the mark scheme or in the generic level descriptors for the question  the standard of response required by a candidate as exemplified by the standardisation scripts. GENERIC MARKING PRINCIPLE 2: Marks awarded are always whole marks (not half marks, or other fractions). GENERIC MARKING PRINCIPLE 3: Marks must be awarded positively:  marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate  marks are awarded when candidates clearly demonstrate what they know and can do  marks are not deducted for errors  marks are not deducted for omissions  answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the question as indicated by the mark scheme. The meaning, however, should be unambiguous. GENERIC MARKING PRINCIPLE 4: Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level descriptors.

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 3 of 12 GENERIC MARKING PRINCIPLE 5: Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may be limited according to the quality of the candidate responses seen). GENERIC MARKING PRINCIPLE 6: Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or grade descriptors in mind.

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 4 of 12 Please note the following further points: The words in bold in the mark scheme are important text that needs to be present, or some notion of it needs to be present. It does not have to be the exact word, but something close to the meaning. If a word is underlined, this exact word must be present. A single forward slash means this is an alternative word. A double forward slash means that this is an alternative mark point. Ellipsis (…) on the end of one-mark point and the start of the next means that the candidate cannot get the second mark point without being awarded the first one. If a mark point has an ellipsis at the beginning, but there is no ellipsis on the mark point before it, then this is just a follow-on sentence and can be awarded without the previous mark point.

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 5 of 12 Question Answer Marks Section A 1(a)(i) Many correct answers, the name used must be meaningful. The name given is an example only. One mark per mark point, max three Constant AdultCostOneDay Value 20.00 Use Storing the cost of an adult ticket for one day 3 1(a)(ii) Many correct answers, the name used must be meaningful. The name given is an example only. One mark per mark point, max three Variable NumberOfTickets // NumberOfAdultTickets Data type Integer Use Inputting the number of tickets purchased // Inputting the number of adult tickets purchased 3 1(b) One mark per mark point, max three MP1 using an array or variables // lookup // input today’s date MP2 use a loop / FOR / REPEAT / WHILE statement MP3 … to output / display today’s date / today using a suitable message MP4 … and the 6/7 following dates/days // loop 6/7 times or MP5 using an array or variables // lookup // input today’s date MP6 array/ variables contains all the days of the week / the next seven days or dates MP7 attempt to output / display available days using a suitable message(s) 3 1(c) One mark per mark point, max two MP1 method used to allocate a new number, e.g. initialise a variable or counter // select a random number MP2 how it ensured uniqueness, e.g. every booking number is one larger than the previous number // check existing bookings to ensure it hasn’t been used before 2

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 6 of 12 Question Answer Marks 1(d) One mark per mark point, max six MP1 initialise a running total for the cost of the booking MP2 input (with prompt) the number of tickets MP3 … attempt to identify type of ticket MP4 … add the cost of tickets to the running total MP5 ability to book several types of ticket MP6 attempt to check that the number of children booked is less than or equal to twice the number of adults MP7 attempt to identify type of attraction MP8 input with prompt the number of selected attractions required MP9 … check that this number is not greater than the total number of tickets booked MP10 … add the cost of the attractions to the (running) total Example answer TotalCost  0 TotalPeople  0 OUTPUT "Do you want single tickets? Y/N" INPUT Single IF Single = "Y" THEN FOR Type  1 TO 3 // adults, children and seniors REPEAT Flag  True OUTPUT "How many ",TicketDecription[Type], " tickets" INPUT NumberOfTickets[Type] IF Type = 2 THEN IF NumberOfTickets[2] > 2 * NumberOfTickets[1] THEN Flag  FALSE OUTPUT "Too many children" ENDIF ENDIF UNTIL NumberOfTickets[Type] >= 0 AND Flag TotalCost  TotalCost + TicketPrice[Type] * NumberOfTickets[Type] 6

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 7 of 12 Question Answer Marks 1(d) TotalPeople  TotalPeople + NumberOfTickets[Type] NEXT Type ENDIF OUTPUT "Do you want a family ticket? Y/N" INPUT Family IF Family = "Y" THEN OUTPUT "How many?" INPUT NumberOfTickets[4] TotalCost  TotalCost + TicketPrice[4] * NumberOfTickets[4] TotalPeople  TotalPeople + NumberOfTickets[4] * 5 ENDIF OUTPUT "Do you want a group ticket? Y/N" INPUT Group IF Group = "Y" THEN OUTPUT "How many people in the group?" INPUT NumberOfTickets[5] TotalCost  TotalCost + TicketPrice[5] * NumberOfTickets[5] TotalPeople  TotalPeople + NumberOfTickets[5] ENDIF REPEAT OUTPUT "How many people would like to see the lion feeding?" INPUT LionFeedingNumber IF TotalPeople >= LionFeedingNumber THEN TotalCost  TotalCost + LionFeedingNumber * LionfeedingPrice ENDIF OUTUT "How many people would like to see the penguin feeding?" INPUT PenguinFeedingNumber IF TotalPeople >= PenguinFeedingNumber THEN TotalCost  TotalCost + PenguinFeedingNumber * PenguinfeedingPrice ENDIF UNTIL TotalPeople >= PenguinFeedingNumber AND TotalPeople >= LionFeedingNumber

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 8 of 12 Question Answer Marks 1(e) Explanation One mark per mark point, max three MP1 use of selection (or any other method) to identify bookings with 2 or more adults and/or seniors and 2 (allow 3) or more children MP2 calculating new price including family ticket(s) for booking / tickets sold MP3 … use of condition to compare price of family ticket(s) to price of ordinary tickets / group ticket(s) … MP4 … identifying best value / lowest cost 3

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 9 of 12 Question Answer Marks Section B 2(a) One mark per mark point, max three  line 8 / PassCheck  TRUE correction PassCheck  FALSE  line 12 / IF Password <> Password correction IF Password2 <> Password // IF Password <> Password2  line 18 / UNTIL PassCheck OR Attempt <> 3 correction UNTIL PassCheck OR Attempt = 3 / UNTIL PassCheck OR Attempt >= 3 3 2(b) One mark check, one mark matching description, max four Check: validation // length check Description length check // checks number of characters in password Check: verification // double entry Description double entry // comparison that two inputs are the same 4 2(c) One mark per set, one mark matching reason, max four Set 1 – any appropriate example e.g. “small” Reason must follow through from the password given e.g. abnormal data will be rejected Set 2 – any different appropriate example e.g. “password” and “password” Reason must be different and follow through from the password given e.g. normal data will be accepted 4 Question Answer Marks 3(a) One mark per mark point, max two  a list / one column of items  … of the same data type  … stored under a single identifier  … with a single index to identify each element One mark for an example of a declaration  example e.g. DECLARE MyArray[1:10] OF INTEGER 3

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 10 of 12 Question Answer Marks 3(b) One mark per mark point, max two  using a counter to index the array  so that the same code can be repeatedly used to check every element // every element can be checked in a loop 2 Question Answer Marks 4(a) One mark for each correct column Counter Hot Cold Serve Temp Error OUTPUT 0 0 0 0 1 1 75 2 2 78 3 3 84 4 1 87 Too Hot 5 2 91 Too Hot 6 4 80 7 5 75 8 6 70 9 7 65 10 1 62 Too Cold -1 30 30 7

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 11 of 12 Question Answer Marks 4(b)  include a message to explain the value output / e. g. “The percentage of meals not served” // outputting Hot, Cold and Serve 1 4(c)  updating the Serve variable // Serve  Serve + 1 1

0984/22 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2022 © UCLES 2022 Page 12 of 12 Question Answer Marks 5(a) One mark per mark point, max four  correct rows Field and Table  correct row Show  correct Criteria for SingleUse or/and Uses  correct Criteria for StockLevel less than ReorderLevel Field: ItemNumber Description SingleUse StockLevel Table: NURSE NURSE NURSE NURSE Sort: Show:     Criteria: True <[ReorderLevel] or: Or Field: ItemNumber Description Uses StockLevel Table: NURSE NURSE NURSE NURSE Sort: Show:     Criteria: = 1 <[ReorderLevel] or: 4 5(b) the field Uses already shows this information // duplication of data // redundant data 1