Algorithms

Algorithms are the heart of computer science — step-by-step procedures for solving problems and performing computations. In OCR A-Level Computer Science, you'll study how to design, analyse, and implement algorithms, focusing on efficiency and correctness. This topic covers sorting and searching algorithms, algorithmic thinking, and the use of standard algorithms to solve problems. Understanding algorithms is crucial because they underpin everything from simple data processing to complex artificial intelligence, and they form the basis for writing efficient code in any programming language.

The OCR specification requires you to know specific algorithms such as binary search, linear search, bubble sort, insertion sort, merge sort, and quick sort. You must be able to trace these algorithms, compare their time and space complexities using Big O notation, and explain when to use each one. Beyond sorting and searching, you'll also explore algorithms for data structures like stacks, queues, trees, and graphs, including traversal methods (depth-first and breadth-first search). This knowledge is directly assessed in Paper 1 (Computer Systems) and Paper 2 (Algorithms and Programming), where you may be asked to write pseudocode or trace an algorithm.

Mastering algorithms is not just about memorising steps — it's about developing computational thinking skills. You'll learn to decompose problems, recognise patterns, and design efficient solutions. This topic connects to many others: data structures, programming techniques, and even the theory of computation. By understanding algorithms deeply, you'll be better prepared for university-level computer science and real-world programming challenges.