Lesson 23 — Quicksort

Quicksort: pick a pivot, split, repeat

Quicksort is a divide and conquer sort: pick a pivot value, split the list into items smaller than it, equal to it, and bigger than it, then sort the two outer parts the same way (recursion). Lists of length 0 or 1 are already sorted — the base case.

small = [n for n in nums if n < pivot]

On average it runs in O(n log n) — far faster than bubble sort on big data.

Why it matters: variants of quicksort sit inside many standard libraries' sort functions.