icon

Plus Advent Calendar Door #18: Happy birthday Quicksort!

Share this page

When you are buying online you usually get the option to see the items you searched for ordered by price, average customer rating, or perhaps date. If you have ever tried to put a bunch of things (e.g. books on your shelf) in order, you'll know it takes time. This is why the world owes a huge debt of gratitude to computer scientist Tony Hoare for inventing Quicksort — a famous sorting algorithm which celebrated its 60th birthday this year.

Tony Hoare

Tony Hoare, the inventor of Quicksort, in 2011. Photo: Rama, CC BY-SA 2.0 FR

Hoare developed Quicksort long before online shopping had even been conceived of, but it's still hailed as one of the best sorting algorithms and implemented in many programming languages and libraries. Its anniversary was celebrated at the Isaac Newton Institute for Mathematical Sciences (INI) in Cambridge this year.

On that occasion we were lucky enough to (virtually) met Hoare to ask him about his most famous brain child, whose invention started on a couch.

To find out more about this, and the beautiful algorithm itself, carry on reading here.

Return to the Plus advent calendar 2021.


This article is part of our collaboration with the Isaac Newton Institute for Mathematical Sciences (INI), an international research centre and our neighbour here on the University of Cambridge's maths campus. INI attracts leading mathematical scientists from all over the world, and is open to all. Visit www.newton.ac.uk to find out more.

INI logo

Read more about...
  • Want facts and want them fast? Our Maths in a minute series explores key mathematical concepts in just a few words.

  • As COP28, the 2023 United Nations Climate Change Conference, kicks off we look at how maths can help understand the climate crisis.

  • How do you create dramatic film out of mathematics? We find out with writer and director Timothy Lanzone.

  • Mathematics plays a central role in understanding how infectious diseases spread. This collection of articles looks at some basic concepts in epidemiology to help you understand this fascinating and important field, and set you up for further study.

  • Find out why the formula we use to work out conditional probabilities is true!

  • We talk about a play that explores the fascinating mathematical collaboration between the mathematicians GH Hardy and Srinivasa Ramanujan.