Compare algorithms for finding the convex hull.

Convex hull is smallest convex polygon containing all points. Graham scan: sort by polar angle from lowest point, process in order keeping only left turns. O(n log n). Jarvis march (gift wrapping): start from leftmost, repeatedly find point making smallest angle. O(nh) where h is hull points. Chan's algorithm: optimal O(n log h) combining both. QuickHull: divide-and-conquer, average O(n log n), worst O(n^2). Choice depends on expected output size.