The Joys of Hashing

1. Front Matter

   Pages i-xi

   PDF

2. The Joys of Hashing

   • Thomas Mailund

   Pages 1-5

3. Hash Keys, Indices, and Collisions

   • Thomas Mailund

   Pages 7-20

4. Collision Resolution, Load Factor, and Performance

   • Thomas Mailund

   Pages 21-47

5. Resizing

   • Thomas Mailund

   Pages 49-99

6. Adding Application Keys and Values

   • Thomas Mailund

   Pages 101-137

7. Heuristic Hash Functions

   • Thomas Mailund

   Pages 139-171

8. Universal Hashing

   • Thomas Mailund

   Pages 173-198

9. Conclusions

   • Thomas Mailund

   Pages 199-200

10. Back Matter

    Pages 201-206

    PDF

Build working implementations of hash tables, written in the C programming language. This book starts with simple first attempts devoid of collision resolution strategies, and moves through improvements and extensions illustrating different design ideas and approaches, followed by experiments to validate the choices. 


Hash tables, when implemented and used appropriately, are exceptionally efficient data structures for representing sets and lookup tables, providing low overhead, constant time, insertion, deletion, and lookup operations. 


The Joys of Hashing walks you through the implementation of efficient hash tables and the pros and cons of different design choices when building tables. The source code used in the book is available on GitHub for your re-use and experiments.


What You Will Learn

• Master the basic ideas behind hash tables
  
• Carry out collision resolution, including strategies for handling collisions and their consequences for performance
  
• Resize or grow and shrink tables as needed
  
• Store values by handling when values must be stored with keys to make general sets and maps

Who This Book Is For


Those with at least some prior programming experience, especially in C programming.

• hash
• tables
• programming
• C
• language
• data
• maps
• source
• code

• Aarhus N, Denmark

  Thomas Mailund

Thomas Mailund is an associate professor in bioinformatics at Aarhus University, Denmark. He has a background in math and computer science, including experience programming and teaching in C and R programming languages.  For the last decade, his main focus has been on genetics and evolutionary studies, particularly comparative genomics, speciation, and gene flow between emerging species.

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