Awesome Algorithms

A curated list of awesome places to learn and/or practice algorithms. Inspired by awesome-awesomeness and all the other awesome Awesome libraries.

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Websites you should use to learn classic algorithms

  • A Visual Guide to Graph Traversal Algorithms - Interactive visualisations for learning how graph traversal algorithms work
  • W3School - Data Structures tutorial.
  • CodeChef - Learning DSA by practice on Codechef
  • Algorithm Visualizer - Dozens of animated algorithms (with code), and you can also create your own.
  • Algorithms Visualization - A dense article on Algorithms Visualization.
  • Big-O Cheat Sheet - Big-O complexities of common algorithms used in Computer Science.
  • Code-Drills - Practice problems recommender (includes Codeforces, Codechef and Spoj).
  • CP-Algorithms - Algorithms and data structures especially popular in field of competitive programming.
  • Data Structure Visualizations - Visualize the behavior of Data Structures and play with its operations.
  • Geeks for Geeks - Lots and lots of well explained and implemented algorithms.
  • Path Finding - A visual representation on how algorithms such as A*, IDA*, Breadth-First-Search, Best-First-Search and others describe a path between two points A and B.
  • Programiz - Easy to follow tutorials on data structures and algorithms along with suitable examples.
  • Rosetta Code - A programming chrestomathy site which aims to present implementations of many algorithms and data structures in different programming languages.
  • Sorting Algorithms - Nice and simple animations of sorting algorithms. With short codes and discussions.
  • Stoimen's web log - Some algorithms nicely explained.
  • The Sound of Sorting - The Sound of Sorting - "Audibilization" and Visualization of Sorting Algorithms
  • VisuAlgo - Visualising data structures and algorithms through animation.
  • Wikipedia - Algorithms - Of course!!
  • Wikipedia - Data Structures - and why not ?!!
  • Learnersbucket - Tutorials on data sturctures and algorithms in Javascript.
  • redblobgames - interactive visual explanations of math and algorithms, using motivating examples from computer games.

Online Courses

Free and High Quality Courses Online


The most highly regarded books to learn algorithms

Algorithms and Data structures

Algorithm Analysis

Randomized Algorithms

Cheat Sheets

Github Libraries

Implementations of the most classic algorithms in a wide variety of programming languages

Online Judges

Online Judges to practice what you learned above

  • A2 Online Judge - Online Judge and problem archive.
  • ACM-ICPC Live Archive - Hundreds of problems from previous ACM-ICPC Regionals and World Finals.
  • AIZU ONLINE JUDGE - Japanese Online Judge.
  • Algo Muse - Research based algorithmic problems.
  • AtCoder - Japanese programming contest website.
  • Baekjoon Online Judge - Korean Online Judge. 10000+ problems. Supports 60+ languages.
  • CS Academy - Holds online contests and IOI practice contests
  • CodeChef - More problems and monthly online contests.
  • Codeforces - The only programming contests Web 2.0 platform
  • Codefights - Practive programming and tackle out your next tech interview
  • CodeMarshal - Real world contests online!
  • CodeWars - A website that houses support to solve algorithms in many languages in varying difficulty.
  • CoderByte - A decent website with algorithm challenges from beginner to advanced levels. Supports most of the popular languages like C++, python, javascript, ruby.
  • Firecode - uses machine learning algorithms along with curated real-world interview questions, solutions & a vibrant social community of learners to get you ready for your next coding interview.
  • Coding Blocks - Website that have problems based on Maths, Data Structures, Various Algorithm and also conducts Coding Competition.
  • HackerEarth - Practice alogrithmic problems & challenges and participate in hiring challenges.
  • HackerRank - Featured algorithm and functional programming online judges
  • HiHoCoder - Chinese and English problem solving practice and recruitment challenge site.
  • Infoarena - Romanian Online Judge. 1500+ algorithmic problems
  • Interviewbit - Learn, practice and prepare for interviews.
  • Kattis- Online judge and problem archive
  • LavidaOnlineJudge - Korean Online Judge(Half English). 1300+ problems.
  • Learneroo Algorithms Tutorials - Learn and practice algorithms by solving challenges online.
  • LeetCode - Learn algorithms and prepare for interviews.
  • PKU JudgeOnline - Chinese Online Judge.
  • ProjectEuler - Mathematical problems that can be solved using algorithms (or just a pencil, depends on how much you already know).
  • Rosalind - A platform for learning bioinformatics and programming through problem solving.
  • - Online Judge and contest host with a lot of algorithmic problems in the archive to practice.
  • Snakify - An introductory Python course with 100+ algorithmic problems and a step-by-step debugger (from Russia).
  • SPOJ - More problems.
  • TopCoder - Lots of problems and real world/money worthy problems in Graphic Design, Data Science and Development.
  • Toph - Bangladeshi Online Judge. Holds online contests on a regular basis.
  • URI - Brazilian Online Judge. Not so much problems, but it's growing and it has online contests.
  • UVA - Hundreds of problems (from previous ACM-ICPC Regionals, World Finals and others).
  • Codility - Compete to land coding jobs at top companies


Awesome list of blogs, mainly for competitive programming but you can refer to these when learning a new topic/algorithm


Some tools that can help you in the learning of algorithms


And for the sake of copyleft, here's our license:

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.