CP-Algorithms
A dense reference for algorithms used in programming contests.
CP-Algorithms is a community-maintained reference site covering algorithms, data structures, and mathematical techniques commonly used in competitive programming. Its articles explain the underlying ideas, complexity, and implementation details across topics such as graphs, strings, number theory, geometry, dynamic programming, and data structures.
Why it stands out
- Strong focus on contest-relevant algorithms rather than general software tutorials.
- Broad coverage of advanced topics that are often scattered across textbooks and blog posts.
- Articles are structured for implementation, usually pairing theory with complexity and coding considerations.
- Open community project with visible contribution guidelines and source repository.
Good to know
- Primarily a reference, not an interactive course or online judge with graded practice.
- Content assumes comfort with programming, discrete math, and algorithmic notation.
- Scope is centered on competitive programming, so production engineering tradeoffs are usually outside its focus.
Under the radar: Use the tag index when a technique can live in multiple sections; it can reveal related articles that the sidebar hierarchy may separate.
Photos

Competitive programmers and ICPC-style trainees use it to quickly review algorithm theory and implementation patterns before contests. Look up graph, string, or number-theory techniques while solving online judge problems. Compare multiple variants of a concept, such as shortest paths, flows, or lowest common ancestor methods. Refresh mathematical tools like modular arithmetic, combinatorics, FFT, or linear algebra for coding tasks.
Topic-organized algorithm articles, searchable documentation, navigation by category and tag, coverage of standard contest data structures and math methods, code-oriented explanations, changelog, and public contribution workflow through GitHub.
Alternative listings
A coding learning hub with tutorials, practice, and interview prep.
coding / ProgrammingGeeksforGeeks is a computer science and programming education site covering data structures, algorithms, languages, web development, databases, DevOps, AI, and related technical subjects. It combines reference-style articles with quizzes, coding practice, competitive programming, interview questions, videos, contests, and structured course offerings.
0 votesVisit siteA large open-source reference for algorithms in many languages.
coding / ProgrammingThe Algorithms is a community-maintained collection of data structure and algorithm implementations across 30+ programming languages. It organizes examples such as sorting, searching, graph algorithms, and common data structures, with GitHub-based contribution workflows and community review.
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