Essential algorithms for GCSE and A Level Computer Science

The aim of this book is to provide students and teachers of GCSE, AS & A level Computer Science a comprehensive guide to the algorithms students need to understand for examinations. Each chapter examines a data structure or algorithm explaining how it works, real-world applications, a step-by-step example, pseudocode, actual code in two languages and a description of the space and time complexity.

We have chosen to provide coded solutions in Python 3 because it is the most popular language taught at GCSE, and in Visual Basic Console (2015 onwards) because it is a language that most closely resembles the pseudocode and coded examples students will need to work with in examinations.

This book is appropriate for all English and Welsh Computer Science specifications, check out our up-to-date mapping document for details.

Select the appropriate tile below for additional videos and resources relating to each algorithm.

Fully coded algorithms in Python & Visual Basic

Generic help designing and writing algorithms

Fundamental data structures

Higher order data structures

Searching algorithms

Sorting algorithms

Optimisation algorithms

Algorithm efficiency

What extra is in the book?

This algorithm / data structure has its own dedicated chapter in the book, which includes:

  1. Overview
  2. Typical applications / uses
  3. Typical operations
  4. The algorithm written out in simple-structured English
  5. The algorithm written out in pseudocode
  6. Full code listing Python
  7. Full code listing in Visual Basic
  8. Diagrammatic walk-through
  9. Efficiency discussion with reference to Big-O notation

A hard copy of the book is available on our shop and a free PDF copy is included for all premium subscribers.