Computer Science · Oct / Nov 2022 · Paper 22 · Question 1

Many correct answers, the name used must be meaningful. The name given is an example only.

One mark per mark point, max two

Task 1 – setting up the booking system

Set up suitable data structures to store the car licence numbers and names of visitors who have booked car parking spaces. The data structures should have sufficient capacity to store data for each of the 20 parking spaces for a static period of two weeks. Allow a visitor to request a parking space on any day within the two-week period by entering a number between 1 and 14, inclusive. The system will check that there are spaces available on the day requested, and if so, will ask the visitor to enter their name and car licence number. This data will be stored in the data structures

representing the first available parking space for the day requested. The visitor will be told the number of their parking space.

At the end of the two-week period, allow all of the data to be deleted ready for the next two-week period.

Many correct answers, the name used must be meaningful. The name given is an example only.

One mark per mark point, max two

LicenceNumbers …

… storing the licence numbers of the cars to be parked

One mark per mark point, max two

MP1

use a (range) check to check for values between 1 and 14

MP2

use a (type) check to ensure an integer is entered

MP3

… using an (appropriate) IF/conditional statement

MP4

outputs an error message if a new input is required

MP5

re-enter data using WHILE/REPEAT loop until a valid entry has been made

One mark

MP6

appropriate line of code / construct to answer the question

Example code

INPUT Day

WHILE Day < 1 OR Day > 14 DO

OUTPUT "You must enter a number between 1 and 14 inclusive"

INPUT Day

ENDWHILE

One mark per mark point, max six

MP1

input for day number or to choose accessible parking …

MP2

… both inputs with appropriate prompts

MP3

conditional statement to check if accessible parking is required

MP4

initialisation of variable for the first accessible space

MP5

checking if current array element is an available space

MP6

correct loop to check all array elements for the day

MP7

… until an available space is found (or not)

MP8

input car licence number and name (with or without prompts)

MP9

… and store them in the correct array position(s)

MP10

appropriate output for space available or no space available

MP11

appropriate output for allocated parking space details

Task 2 – adding accessible parking spaces

The visitor car park booking system is to be re-designed to offer accessible parking. Spaces 1 to 5 are named accessible spaces. Spaces 6 to 20 are named general spaces.

Extend your program in Task 1 so that:

The system must work so that visitors requiring accessible parking may be allocated any of the 20 spaces, but visitors who do not need accessible parking may only be allocated general spaces.

Example answer

//Assume LicenceNumber array has been initialised with the null string

OUTPUT "Enter the number of the day in which you require parking "

INPUT Day

OUTPUT "Do you require an accessible space? (Y or N)"

INPUT Accessible

IF Accessible = "Y"

THEN

SpaceAllocated ← FALSE

Space ← (Day - 1) * 20

REPEAT

IF LicenceNumbers[Space] = ""

THEN

OUTPUT "Enter your car licence number "

INPUT LicenceNumbers[Space]

SpaceAllocated ← TRUE

ENDIF

Space ← Space + 1

UNTIL SpaceAllocated OR Space = (Day - 1) * 20 + 20

IF NOT SpaceAllocated

THEN

OUTPUT "No space available"

ELSE

OUTPUT "You are allocated space: ", Space – (Day – 1) * 20

ENDIF

ENDIF

Explanation of how the following could be done:

One mark per mark point, max three

MP1

change the max constant to 560 / 28

MP2

change the output message for the user to say that the range of days entered must be from 1 to 28

MP3

alter the validation to allow an input of 1 to 28

MP4

change the size of the array that stores licence numbers / names so that it can hold the additional data

MP5

ensure that all loops that access the stored data for retrieval or erasing of data include the new full range

Explanation of how the following could be done:

One mark per mark point, max four

MP1

initialise counting variable(s) …

MP2

… for accessible spaces and general spaces before any spaces have been allocated

MP3

increment the counter(s) …

MP4

… for accessible spaces and general spaces

MP5

maintain both counters for the full two-week cycle

MP6

output to show the total number of accessible and general spaces allocated so far, with suitable messages

Section B