TopCoder Prewritten Code
string manipulation
Routines to convert from int/double to string and back, split a string up into a vector of strings, ints, doubles, or a vector of those types.
rabin miller prime test
Rabin-Miller Primality Test, guaranteed to work for all 32-bit integers.
knuth-morris-pratt
Knuth-Morris-Pratt string matching algorithm; search for pattern string within a given text string in linear time and space.
biparite matching
Given a bipartite graph, find a maximum matching.
geometry
Assorted two dimensional geometry routines, including distance between a point and a line, line segment intersection, finding the convex hull of a set of points, determining whether a point is inside a given polygon, etc.