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.

Websites

Websites you should use to learn classic algorithms

Wikipedia - Algorithms - Of course!!
Wikipedia - Data Structures - and why not ?!!
Geeks for Geeks - Lots and lots of well explained and implemented algorithms.
Data Structure Visualizations - Visualize the behavior of Data Structures and play with its operations.
Algorithms Visualization - A dense article on Algorithms Visualization.
Big-O Cheat Sheet - Big-O complexities of common algorithms used in Computer Science.
stoimen's web log - Some algorithms nicely explained.
VisuAlgo - Visualising data structures and algorithms through animation.
Algomation - A didactic, animated, exposition of algorithms.
Algorithmist - The Algorithmist is a resource dedicated to anything algorithms - from the practical realm, to the theoretical realm. There are also links and explanation to problemsets.

Free and High Quality Courses Online

MIT - 6-00sc - An easy and well explained introduction to algorithms.
MIT - 6-006 - Well explained algorithms.
MIT - 6-046j - Similar to the previous one, but with different algorithms.
YogiBearian YouTube Channel - Lots of well explained vidoes on various computer science subjects.
Algorithms: Design and Analysis, Part 1 - Course mainly based on the book "Introduction to Algorithm".
Algorithms: Design and Analysis, Part 2 - Second part, focusing on Greedy and Dynamic paradigms, and NP-Complete problems.
Udacity Intro to Algorithms - Python-based Algorithms course.
Khan Academy Algorithms - Algorithm course ministred by Tomas Cormen and Devin Balkcom.

The most highly regarded books to learn algorithms

Introduction to Algorithms - Essential!
The Algorithm Design Manual - Easy to read and full of real world examples.
Algorithm Design - Pretty straight-forward.
The Art of Computer Programming - The Book.
Elementary Algorithms - An awesome book about algorithms and data structures.
Data Structures Using C - The basic concepts and usages of data structures.
Algorithms - Problems explained with Java, OO good practices, visualizations, and free online resources.

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

Online Judges to practice what you learned above

UVA - Hundreds of problems (from previous ACM-ICPC Regionals, World Finals and others).
SPOJ - More problems.
ACM-ICPC Live Archive - Hundreds of problems from previous ACM-ICPC Regionals and World Finals.
URI - Brazilian Online Judge. Not so much problems, but it's growing and it has online contests.
CodeChef - More problems and monthly online contests.
CodeMarshal - Real world contests online!
ProjectEuler - Mathematical problems that can be solved using algorithms (or just a pencil, depends on how much you already know).
TopCoder - Lots of problems and real world/money worthy problems in Graphic Design, Data Science and Development.
Learneroo Algorithms Tutorials - Learn and practice algorithms by solving challenges online.
Infoarena - Romanian Online Judge. 1500+ algorithmic problems
AIZU ONLINE JUDGE - Japanese Online Judge.
PKU JudgeOnline - Chinese Online Judge.
Rosalind - A platform for learning bioinformatics and programming through problem solving.
LavidaOnlineJudge - Korean Online Judge(Half English). 1300+ problems.
LeetCode - Learn algorithms and prepare for interviews.
HackerRank - Featured algorithm and functional programming online judges
Codeforces - The only programming contests Web 2.0 platform

Some tools that can help you in the learning of algorithms

flow-chart.js - A tool that allows you to create flowcharts that can simulate real algorithms.
interactive-coding-challenges - Interactive, test-driven coding challenges (algorithms and data structures).

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