PMT
A-level
COMPUTER SCIENCE
Paper 1
Monday 12 June 2023 Afternoon Time allowed: 2 hours 30 minutes
Materials
For this paper you must have:
• a computer
• a printer
• appropriate software
• the Electronic Answer Document
• an electronic version and a hard copy of the Skeleton Program
• an electronic version and a hard copy of the Preliminary Material.
You must not use a calculator.
Instructions
• Type the information required on the front of your Electronic Answer Document.
• Before the start of the examination make sure your Centre Number, Candidate Name and
Candidate Number are shown clearly in the footer of every page (also at the top of the front
cover) of your Electronic Answer Document.
• Enter your answers into the Electronic Answer Document.
• Answer all questions.
• Save your work at regular intervals.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 100.
• No extra time is allowed for printing and collating.
• The question paper is divided into four sections.
Advice
You are advised to allocate time to each section as follows:
Section A – 40 minutes; Section B – 20 minutes; Section C – 20 minutes; Section D – 70 minutes.
At the end of the examination
Tie together all your printed Electronic Answer Document pages and hand them to the Invigilator.
Warning
It may not be possible to issue a result for this paper if your details are not on every page of your
Electronic Answer Document.
IB/G/Jun23/E10 7517/1
, PMT
2
Section A
You are advised to spend no longer than 40 minutes on this section.
Enter your answers for Section A in your Electronic Answer Document.
You must save this document at regular intervals.
0 1 Describe the process that should be followed to add an item to a circular queue
implemented as a static data structure using an array.
Your method should deal appropriately with any issues which could arise.
[5 marks]
0 2 Figure 1 shows a logic puzzle.
Figure 1
The following five coloured shapes are placed on a table.
Image of coloured shapes not reproduced here
due to third party copyright restrictions.
Tabitha secretly chooses one of the coloured shapes and:
• tells Walter the colour of the shape she has chosen (pink, yellow or blue)
• tells Lionel the type of shape she has chosen (triangle, circle or square).
Lionel and Walter both know what coloured shapes are on the table.
Lionel knows that Walter has been told the colour chosen by Tabitha.
Walter knows that Lionel has been told the type of shape chosen by Tabitha.
They do not know what the other has been told.
Tabitha first asks Walter and Lionel if they know which coloured shape she
has chosen. They both answer at the same time and say “No”.
Tabitha then asks them again if they know which coloured shape she has
chosen. They both answer at the same time and say “No” again.
Tabitha asks them a third time if they know which coloured shape she has
chosen and they both answer at the same time and say “Yes”.
0 2 . 1 After they have both replied to Tabitha’s first question, what does Lionel now know
about Tabitha’s choice because Walter said “No”?
[1 mark]
IB/G/Jun23/7517/1
, PMT
3
0 2 . 2 After they have both replied to Tabitha’s first question, what does Walter now know
about Tabitha’s choice because Lionel said “No”?
[1 mark]
0 2 . 3 Which coloured shape had Tabitha chosen?
[1 mark]
Turn over for the next question
Turn over ►
IB/G/Jun23/7517/1
, PMT
4
0 3 A binary tree is a type of data structure.
0 3 . 1 State two characteristics that make a tree a binary tree.
[2 marks]
0 3 . 2 Figure 2 shows a binary tree and its representation using an array of records called
Tree. Each record consists of three fields, Data, Left and Right.
Figure 2
Data Left Right
[0] 6 1 4
[1] 3 2 3
[2] 1 -1 -1
[3] 4 -1 -1
[4] 9 -1 -1
Figure 3 shows a subroutine that implements a binary tree search algorithm using the
array Tree. The subroutine parameter, k, is the data item being searched for. The
subroutine returns a Boolean value indicating if the data item being searched for is in
the binary tree or not.
Parts of the algorithm are missing.
Figure 3
SUBROUTINE BTS(k)
Current _____1_____
WHILE Current > ____ 2_____
IF Tree[Current].Data = k THEN
RETURN _____3_____
ELSEIF Tree[Current].Data < k THEN
____ 4_____
ELSE
_____5_____
ENDIF
ENDWHILE
RETURN _____6_____
ENDSUBROUTINE
IB/G/Jun23/7517/1
A-level
COMPUTER SCIENCE
Paper 1
Monday 12 June 2023 Afternoon Time allowed: 2 hours 30 minutes
Materials
For this paper you must have:
• a computer
• a printer
• appropriate software
• the Electronic Answer Document
• an electronic version and a hard copy of the Skeleton Program
• an electronic version and a hard copy of the Preliminary Material.
You must not use a calculator.
Instructions
• Type the information required on the front of your Electronic Answer Document.
• Before the start of the examination make sure your Centre Number, Candidate Name and
Candidate Number are shown clearly in the footer of every page (also at the top of the front
cover) of your Electronic Answer Document.
• Enter your answers into the Electronic Answer Document.
• Answer all questions.
• Save your work at regular intervals.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 100.
• No extra time is allowed for printing and collating.
• The question paper is divided into four sections.
Advice
You are advised to allocate time to each section as follows:
Section A – 40 minutes; Section B – 20 minutes; Section C – 20 minutes; Section D – 70 minutes.
At the end of the examination
Tie together all your printed Electronic Answer Document pages and hand them to the Invigilator.
Warning
It may not be possible to issue a result for this paper if your details are not on every page of your
Electronic Answer Document.
IB/G/Jun23/E10 7517/1
, PMT
2
Section A
You are advised to spend no longer than 40 minutes on this section.
Enter your answers for Section A in your Electronic Answer Document.
You must save this document at regular intervals.
0 1 Describe the process that should be followed to add an item to a circular queue
implemented as a static data structure using an array.
Your method should deal appropriately with any issues which could arise.
[5 marks]
0 2 Figure 1 shows a logic puzzle.
Figure 1
The following five coloured shapes are placed on a table.
Image of coloured shapes not reproduced here
due to third party copyright restrictions.
Tabitha secretly chooses one of the coloured shapes and:
• tells Walter the colour of the shape she has chosen (pink, yellow or blue)
• tells Lionel the type of shape she has chosen (triangle, circle or square).
Lionel and Walter both know what coloured shapes are on the table.
Lionel knows that Walter has been told the colour chosen by Tabitha.
Walter knows that Lionel has been told the type of shape chosen by Tabitha.
They do not know what the other has been told.
Tabitha first asks Walter and Lionel if they know which coloured shape she
has chosen. They both answer at the same time and say “No”.
Tabitha then asks them again if they know which coloured shape she has
chosen. They both answer at the same time and say “No” again.
Tabitha asks them a third time if they know which coloured shape she has
chosen and they both answer at the same time and say “Yes”.
0 2 . 1 After they have both replied to Tabitha’s first question, what does Lionel now know
about Tabitha’s choice because Walter said “No”?
[1 mark]
IB/G/Jun23/7517/1
, PMT
3
0 2 . 2 After they have both replied to Tabitha’s first question, what does Walter now know
about Tabitha’s choice because Lionel said “No”?
[1 mark]
0 2 . 3 Which coloured shape had Tabitha chosen?
[1 mark]
Turn over for the next question
Turn over ►
IB/G/Jun23/7517/1
, PMT
4
0 3 A binary tree is a type of data structure.
0 3 . 1 State two characteristics that make a tree a binary tree.
[2 marks]
0 3 . 2 Figure 2 shows a binary tree and its representation using an array of records called
Tree. Each record consists of three fields, Data, Left and Right.
Figure 2
Data Left Right
[0] 6 1 4
[1] 3 2 3
[2] 1 -1 -1
[3] 4 -1 -1
[4] 9 -1 -1
Figure 3 shows a subroutine that implements a binary tree search algorithm using the
array Tree. The subroutine parameter, k, is the data item being searched for. The
subroutine returns a Boolean value indicating if the data item being searched for is in
the binary tree or not.
Parts of the algorithm are missing.
Figure 3
SUBROUTINE BTS(k)
Current _____1_____
WHILE Current > ____ 2_____
IF Tree[Current].Data = k THEN
RETURN _____3_____
ELSEIF Tree[Current].Data < k THEN
____ 4_____
ELSE
_____5_____
ENDIF
ENDWHILE
RETURN _____6_____
ENDSUBROUTINE
IB/G/Jun23/7517/1
