AQA_2024: A-level Computer Science - Paper 1 (June 2024 - Merged Question Paper and Marking Scheme)

AQA_2024: A-level Computer Science - Paper 1 (June 2024 - Merged Question Paper and Marking Scheme) A-level COMPUTER SCIENCE Paper 1 June 2024 Preliminary Material To be opened and issued to candidates on or after 1 September 2023, subject to the instructions given in the Teacher’s Notes (7517/1/TN). Note  The Preliminary Material and Skeleton Program are to be seen by candidates and their teachers only, for use during preparation for the examination on 10 June 2024. They cannot be used by anyone else for any other purpose, other than that stated in the instructions issued, until after the examination date has passed. They must not be provided to third parties. Information  A Skeleton Program is provided separately by your teacher and must be read in conjunction with this Preliminary Material.  You are advised to familiarise yourselves with the Preliminary Material and Skeleton Program before the examination.  A copy of this Preliminary Material, the Skeleton Program and the Data files , , and will be made available to you in hard copy and electronically at the start of the examination.  You must not take any copy of the Preliminary Material, Skeleton Program or any other material into the examination room. For A-level Computer Science Paper 1 (June 2024), which focuses on Theory of Computer Science, the following are the key areas you should revise: 1. Fundamentals of Programming:  Programming Concepts: Understand data types (integer, real, string, boolean), variables, constants, operators, and control structures (if-else, loops, case statements).  Data Structures: Be comfortable working with arrays, lists, queues, stacks, and linked lists. Know operations like insertion, deletion, and searching for these structures.  Subprograms: Understand the use of functions and procedures. Be able to explain the difference between them and know the importance of parameters and return values.  File Handling: Understand how to read and write to files, handle binary files, and use file handling functions for various tasks. 2. Algorithms and Problem Solving:  Algorithm Design: Focus on designing efficient algorithms to solve problems. Practice pseudocode and flowcharts to represent your algorithm.  Sorting and Searching: o Sorting Algorithms: Know how to implement and analyze bubble sort, merge sort, quick sort, and insertion sort. o Searching Algorithms: Practice linear search and binary search, understand their time complexities (O(n) and O(log n), respectively).  Recursion: Be able to write recursive solutions for problems (e.g., factorials, Fibonacci sequence). Understand the base case and recursive calls.  Big O Notation: Understand how to analyze and compare algorithm efficiency in terms of time complexity and space complexity using Big O notation. 3. Data Representation:  Binary and Hexadecimal: Convert between binary, hexadecimal, and decimal. Understand binary arithmetic operations (addition, subtraction).  Character Representation: Be familiar with ASCII, Unicode, and how characters are represented in memory.  Data Structures in Memory: Know how arrays and linked lists are represented in memory and how to access and manipulate them. 4. Computer Systems:  Hardware Components: Be familiar with the functions of CPU, memory (RAM), input/output devices, secondary storage, and their interactions.  Von Neumann Architecture: Understand the fetch-decode-execute cycle, control unit, ALU (Arithmetic 5. Networking:  Network Topologies: Understand star, bus, ring, and mesh topologies, and their advantages/disadvantages.  Protocols: Understand TCP/IP, HTTP, FTP, DNS, IMAP, and how data is transferred between systems. 6. Databases:  Relational Databases: Understand the concept of tables, primary keys, foreign keys, and SQL operations such as SELECT, INSERT, UPDATE, DELETE. 7517/1/PM IB/G/Jun24/G4001/E5 2 INSTRUCTIONS FOR CANDIDATES Electronic Answer Document Answers for all questions in all sections must be entered into the word-processed document made available to you at the start of the examination and referred to in the question paper rubrics as the Electronic Answer Document. Preparation for the examination You should ensure that you are familiar with the Preliminary Material and the Skeleton Program for your programming language. IB/G/Jun24/7517/1/PM 3 Symbol Puzzle Symbol Puzzle is a simple puzzle where the user places symbols into a grid, trying to maximise their score as they do so. The user is allowed to place a specified number of symbols (38 in the standard puzzle) into the grid. The puzzle is finished when the last symbol has been placed. To score points, the user must place symbols into cells in the grid so that they match a pattern. In the standard puzzle the user is able to use the symbols Q, T and X. To score 10 points using the symbol Q the user needs to place five Q symbols in a 33 section of the grid so that they match the pattern shown in Figure 1. Figure 1 Q Q Q Q Q To score 10 points using the symbol T the user needs to place five T symbols in a 33 section of the grid so that they match the pattern shown in Figure 2. Figure 2 T T T T T To score 10 points using the symbol X the user needs to place five X symbols in a 33 section of the grid so that they match the pattern shown in Figure 3. Figure 3 X X X X X Turn over ► IB/G/Jun24/7517/1/PM 4 When the user has successfully created one of the allowed patterns within a 33 section of the grid, they are no longer allowed to place the symbol used in that pattern in any of the other cells in that 33 section. However, other symbols can still be placed in empty cells within that 33 section. Some cells are blocked, denoted by the symbol @. The user is not able to place a symbol in a blocked cell. In the standard puzzle, the number of blocked cells and the position of each blocked cell is generated randomly. An example of a starting grid for the standard puzzle is shown in