Programming pearls, column 1: Cracking the oyster.

Programming Pearls is a forthcoming bimonthly column in Communications of the ACM devoted to various aspects of computer programming. This first column concentrates on the method of extracting a clean computational problem from a messy real problem; it is based on a single case study that arose in a particular application. The column shows one solution to the problem, draws several general principleds from the exercise, and then provides the reader with problems suitable for testing new- found programming expertise.