Published in The Computer Journal in 1962, this paper by Tony Hoare presents Quicksort, a method for sorting items held in a computer store. Hoare had devised the technique in 1959-1960 while working on the machine translation of languages.

The algorithm sorts by partitioning. An element is chosen as a pivot, and the remaining items are rearranged so that those smaller than the pivot precede it and those larger follow it. The two resulting sections are then sorted by the same procedure, applied recursively until each section contains a single item.

The paper examines the algorithm’s efficiency, including the number of comparisons and exchanges required, and considers its performance on average and in the worst case. Quicksort became one of the most widely used sorting algorithms, valued for its speed and economical use of storage.