Open-source alternatives to LeetCode

This project is an algorithm interview preparation guide and reference library. It provides a curated collection of solved programming problems and data structure implementations designed for technical interview practice and competitive programming study. The repository distinguishes itself by organizing coding challenges through a system of patterns, difficulty levels, and company-based filtering. It includes instructional resources such as algorithmic concept notes and video explanations to supplement the solution sets. The library covers a wide range of computational areas, including adva

This project is a comprehensive reference for algorithms and data structures used to solve complex computational problems in competitive programming. It serves as a technical resource for implementing advanced mathematical programming, computational geometry, and graph theory. The repository provides detailed implementation guides for diversifying algorithmic techniques, including top-down and bottom-up dynamic programming optimization, number theory, and linear algebra. It features specific guides for complex tasks such as constructing planar graphs, solving linear Diophantine equations, and

This project is a LeetCode solution repository and algorithm implementation library. It provides a collection of solved coding challenges and optimized algorithmic patterns designed for academic and professional study. The repository serves as a competitive programming study guide, focusing on the time and space complexity of implementations across multiple programming languages. It provides reference solutions for data structure problems to assist with technical interview preparation and competitive programming practice. The content is organized through a language-specific folder hierarchy

This project is a comprehensive library of reference implementations for fundamental data structures and algorithms, designed to support technical interview preparation and software engineering assessments. It provides a structured collection of computational techniques for solving complex problems involving arrays, strings, graphs, trees, and mathematical analysis. The library distinguishes itself by offering specialized implementations for advanced topics, including concurrent programming patterns and geometric algorithms. It features thread-safe primitives for managing shared state and tas

algorithm-base is an educational library and study guide designed for simulating algorithms and studying data structures. It functions as an execution visualizer that renders step-by-step state changes and pointer updates through animated simulations to illustrate how data movement works. The project distinguishes itself by mapping conceptual logic directly to multi-language source code implementations. It utilizes a comparative analysis framework to evaluate different algorithmic strategies based on stability, time complexity, and space complexity, while organizing problems by underlying mec

algs4 is a Java data structures library and algorithm reference collection designed as the source code for a standard computer science textbook curriculum. It provides a comprehensive suite of fundamental implementations for sorting, searching, and core data organization. The project serves as a graph theory framework, offering tools for representing directed and undirected graphs and performing complex traversals and pathfinding. It also includes a broad sorting algorithm suite and a specialized library of Java data structures, including stacks, queues, priority queues, and symbol tables. I

This project is a data structures and algorithms library providing a collection of fifty standard code implementations for managing data and solving common computational problems. It serves as an algorithm implementation reference and study resource for educational use. The codebase covers graph theory implementations for modeling networks and performing searches, as well as string pattern matching libraries for the retrieval of character sequences. It includes a collection of hierarchical data structures, such as binary search trees and priority heaps, and provides optimized solutions for dy

This project is a LeetCode solution repository and algorithm reference library. It provides a structured collection of solved coding challenges that demonstrate recurring computational strategies, data structure implementations, and complexity optimizations used for technical interview preparation and competitive programming study. The repository transforms structured source code and technical explanations into professional PDF guides using a LaTeX technical documentation system. To ensure consistent typography and environment settings across different systems, the project utilizes a containe

This project is a library of source code implementations designed to solve algorithmic challenges and mathematical problems. It serves as a collection of solved LeetCode problems, providing a reference for data structure usage and efficient logic. The repository is a polyglot code collection, implementing the same algorithmic logic across various programming environments, including general-purpose languages, SQL for database queries, and Bash for shell scripting. The content covers a broad range of computational tasks, including data querying, text processing, and the implementation of compl

AlgorithmsByPython is a reference library and educational repository providing runnable Python implementations of computer science fundamentals. It serves as a comprehensive guide for algorithmic patterns, core data structures, and solutions for competitive programming and technical interview challenges. The project distinguishes itself by offering a wide array of reference implementations, including a dedicated set of solutions for common LeetCode problems. It focuses on translating theoretical computational logic into practical Python code for educational and practical use. The repository

This is a collection of classic computer science algorithms and data structures implemented from scratch in JavaScript. The project provides reference implementations of fundamental concepts including sorting algorithms, binary search, linked lists, and binary search trees, all built as standalone pure functions with no external dependencies. The implementations cover a range of data structures, including singly-linked, doubly-linked, and circular linked lists with full traversal and mutation operations, as well as binary search trees supporting insertion, deletion, and search. Sorting algori

This project is an algorithm template library and coding interview study guide providing reusable code patterns for common data structures and algorithms. It serves as a reference for optimized strategies and a structured learning path to build proficiency in algorithmic problem solving and competitive programming. The library focuses on standardized implementations of key algorithmic patterns, including sliding windows, backtracking, dynamic programming, and binary search. It provides specific templates for managing binary search trees, searching rotated sorted arrays, and executing divide-a

This project is a C++ algorithm implementation library and educational codebase that translates theoretical textbook pseudocode into verified, executable source code. It serves as a collection of reference implementations designed to demonstrate the practical application of classic computer science theories through a structured repository of computational algorithms. The library utilizes template-based generic programming and the C++ Standard Template Library to ensure implementations remain type-safe and flexible across different data types. To ensure correctness, the project includes an aut

This project is a comprehensive collection of common computer science algorithms and data structures implemented in Swift. It serves as an educational reference and library for studying computational complexity, algorithmic logic, and data structure engineering through practical code examples. The repository provides a wide suite of data structure implementations, including various types of linked lists, heaps, hash tables, and an extensive range of hierarchical trees such as Red-Black, B-Tree, and Splay trees. It also covers diverse sorting and searching techniques, from basic bubble sort to

This project is a comprehensive study guide and reference repository designed to prepare software engineers for technical interviews. It provides a structured collection of fundamental computer science concepts, algorithm implementations, and system design principles, serving as a centralized resource for reviewing the core knowledge required for engineering assessments. The repository distinguishes itself by offering language-agnostic concept modeling and modular knowledge categorization, which allows candidates to navigate complex topics efficiently. It covers a broad spectrum of technical

This repository serves as a comprehensive library for algorithmic problem solving, providing reference implementations for fundamental computer science challenges. It is designed as a resource for technical interview preparation and competitive programming training, focusing on the mastery of common patterns and data structures required for coding assessments. The project distinguishes itself by offering solutions that emphasize idiomatic Python usage and performance optimization. It covers a wide range of algorithmic techniques, including greedy selection, dynamic programming, graph theory,

This project is a comprehensive collection of C++ libraries and toolkits providing reference implementations for data structures, graph algorithms, and bitwise logic. It serves as a C++ algorithm reference containing over 180 solved coding problems and a specialized toolkit for competitive programming. The repository distinguishes itself through extensive low-level bit manipulation libraries for parity checks, endianness detection, and XOR-based logic. It also provides a wide array of reference solutions for complex algorithmic challenges involving backtracking, graph theory, and dynamic prog

This project is a computer science educational resource and library providing implementations of data structures and algorithms in JavaScript. It serves as an algorithm implementation reference and a toolkit for building foundational data containers, including a collection of sorting algorithms and a guide for learning time and space complexity. The project differentiates itself by pairing class-based implementations with Big O analysis to illustrate asymptotic complexity. It includes a non-linear data structure toolkit featuring self-balancing trees, hash maps, and graphs, alongside comparis

This is a collection of classical algorithms and data structures implemented as a header-only C++ library. It provides a suite of tools for general algorithm implementation, including data structure management, graph theory analysis, and string processing. The library is distinguished by its specialized toolkits for cryptographic hashing and encoding, featuring implementations of MD5, SHA-1, and Base64. It also includes advanced capabilities for high-performance string processing via suffix trees and arrays, as well as computational number theory for primality testing and arbitrary-precision

This is a collection of standard data structures and algorithmic implementations written in Rust. It provides a suite of specialized libraries designed for competitive programming and systems engineering. The project is organized into distinct toolkits for graph theory, number theory, range queries, and string processing. It includes implementations for computing shortest paths and network flows, performing primality tests and modular arithmetic, and managing associative range queries. The library covers broad computational areas including signal processing via fast Fourier transforms, text

This project is a LeetCode solution repository containing a collection of algorithmic and database problem solutions. It serves as an algorithm implementation guide and a competitive programming reference, providing optimized code to demonstrate data structure usage and efficient coding patterns. The repository includes solutions for complex computational challenges implemented in multiple programming languages and a collection of SQL queries for data retrieval and manipulation across various difficulty levels. These resources are designed for competitive programming study and technical inter

This project is a comprehensive, community-maintained knowledge base and toolkit designed for competitive programming. It serves as a centralized repository for algorithmic theory, data structures, and mathematical techniques, providing a structured reference for informatics and collegiate programming competitions. The project distinguishes itself by integrating educational content with a robust suite of automation utilities. It provides a complete workflow for competitive programming, including tools for automated test case generation, solution verification, and direct interaction with onlin

This repository serves as a comprehensive resource for competitive programming and technical interview preparation. It provides a structured collection of source code implementations for fundamental data structures and classic algorithmic problems, designed to help developers master core computer science concepts and efficient coding strategies. Beyond standard problem-solving, the project distinguishes itself by integrating software design patterns into its algorithmic implementations. It demonstrates how to apply structural and behavioral patterns—such as decorators, observers, and singleto

This project is a comprehensive reference guide for computer science fundamentals, providing structured summaries of essential data structures and algorithmic principles. It serves as a technical resource for developers to review core programming concepts, memory layouts, and operational characteristics required for software development and technical assessments. The collection distinguishes itself by offering concise, implementation-focused documentation for a wide range of standard techniques. It covers the mechanics of various sorting and searching algorithms, graph and tree traversal stra

This project is a JavaScript algorithm library and computer science reference. It provides a collection of standard computational logic patterns and data structure implementations, including linked lists, trees, and graphs, for both educational and practical use. The codebase serves as a technical interview study guide, offering a practical resource for practicing common coding challenges and data structure manipulations. It is designed for computer science education, allowing users to study how classic algorithms work by reviewing and running implementations of established logic patterns. T

This project is a comprehensive suite of Java-based implementations for standard computer science algorithms, data structures, graph analysis, and mathematical computations. It provides a collection of reference implementations for fundamental data containers, including trees, heaps, maps, tries, and lists, alongside common sorting and searching routines. The library includes a specialized suite for graph network analysis, covering shortest paths, minimum spanning trees, and maximum flow. It also provides mathematical utilities for prime testing, modular arithmetic, and Fast Fourier Transform

CodingInterviewChinese2 is a collection of source code implementations for common algorithmic challenges and data structures designed for technical coding interviews. It serves as an algorithm interview solution set and a technical interview study guide, providing C++ programming examples that demonstrate the logic and efficiency required for software engineering roles. The repository functions as a competitive programming study guide and a data structures reference. It provides solved programming exercises and technical interview code samples to help users master the problem-solving patterns