The study of Algorithms is the heart of Computer Science. Algorithms provide a clear, unambiguous means to solve a particular problem. In many instances there is no single correct algorithm for solving a programming contest problem. In many instances there are one or more known algorithms or strategies for solving a programming contest problem. Part of the strategy in a programming contest is having a solid background in classical algorithms, and being able to employ them quickly and accurately.

This section is devoted to classical algorithms that could be encountered in competitive programming settings.

• Sieve of Eratosthenes