The Quicksort algorithm

In the early 1960s, British computer scientist Charles Antony Richard Hoare developed the Quicksort algorithm for sorting a list into a sequence. This one is ascending:

1. Pick any element, called a "pivot," from the list.

2. Pick in turn every other element, comparing each to the pivot. If the element is less than the pivot, put it above the pivot. If it is greater, put it below. At the end of that pass through the list, the pivot is now in its final correct place.

3. In the group of elements above the pivot, pick another pivot and repeat Step 2. In the group below the original pivot, pick a third pivot and repeat Step 2. Now three elements have been sorted into their correct positions.

4. Repeat the entire process, on successively smaller groups, until the whole list is in sequence.