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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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Awesome Algorithms

Websites

Websites you should use to learn classic algorithms

A Visual Guide to Graph Traversal Algorithms - Interactive visualizations 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 are especially popular in the 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 of 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 that 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 structures and algorithms in Javascript.
redblobgames - interactive visual explanations of math and algorithms, using motivating examples from computer games.

Youtube Playlists

High Quality Courses and tutorials on youtube

Tim Roughgarden. Algorithms Illuminated - Tim Roughgarden, a pioneer of computer science, offers a companion to his book, with lecture videos and slides.
FreeCodeCamp - Algorithms and Data Structures Tutorial - Full Course for Beginners - Complete beginner friendly Algorithms and Data Structures Tutorial with mindblowing animation.
Abdul Bari - Introduction to Algorithm - This playlist is so much informative and provide simulation with code example. As like as you are in a class.
Jenny's Lectures- Algorithm - Another complete algorithm playlist from basic level to intermediate. Easy explanation and simulation.

Online Courses

Free and High-Quality Courses Online

Algorithms: Divide and Conquer, Sorting and Searching, and Randomized Algorithms - The primary topics are: asymptotic ("Big-oh") notation, sorting and searching, divide and conquer, and randomized algorithms.
Algorithms: Graph Search, Shortest Paths, and Data Structures - The primary topics are: data structures, graph primitives, and their applications.
Algorithms: Greedy Algorithms, Minimum Spanning Trees, and Dynamic Programming - The primary topics are: greedy algorithms and dynamic programming.
Algorithms: Shortest Paths Revisited, NP-Complete Problems and What To Do About Them - The primary topics are: shortest paths, NP-completeness and what it means for the algorithm designer, and strategies for coping with computationally intractable problems.
Algorithms, Part I - This course covers the essential information that every serious programmer needs to know about algorithms and data structures. Part I covers elementary data structures, sorting, and searching algorithms.
Algorithms, Part II - Part II focuses on graph- and string-processing algorithms.
Khan Academy Algorithms - Algorithm course ministered by Tomas Cormen and Devin Balkcom.
MIT - 6-006 - Well explained algorithms.
MIT - 6-046j - Similar to the previous one, but with different algorithms.
MIT - 6-00sc - An easy and well-explained introduction to algorithms.
MIT 18-409 - Topics in Theoretical Computer Science: An Algorithmist's Toolkit - It covers a collection of geometric techniques that apply broadly in modern algorithm design.
Udacity Intro to Algorithms - Python-based Algorithms course.
Algorithms in Motion - Beginner's algorithms course with fun illustrations, based on the book Grokking Algorithms
~~YogiBearian YouTube Channel - Lots of well-explained videos on various computer science subjects.~~ Account terminated due to violations of Youtube Policies.

Books

The most highly regarded books to learn algorithms

Algorithms and Data structures

Algorithm Design - Pretty straightforward.
Algorithms - Problems explained with Java, OO good practices, visualizations, and free online resources.
Algorithms and Data Structures in JavaScript - Classical algorithms and data structures implemented and explained using JavaScript.
Algorithms in a Nutshell - by George T. Heineman.
Classic Computer Science Problems in Python -This great book presents dozens of coding challenges, ranging from simple tasks to clustering data using k-means.
Data Structures and Algorithms Made Easy - A great way to implement algorithms with their specific programmable tasks.
Data Structures Using C - The basic concepts and usages of data structures.
Elementary Algorithms - An awesome book about algorithms and data structures.
Grokking Algorithms - An illustrated book on algorithms with practical examples.
Introduction to Algorithms - Essential!
Real World Algorithms: A Beginner's Guide - An introduction to algorithms for readers with no background in advanced mathematics or computer science.
Swift Algorithms & Data Structures - A practical guide to concepts, theory, and code.
The Algorithm Design Manual - Easy to read and full of real-world examples.
The Art of Computer Programming - The Book.
Structure and Interpretation of Computer Programs
Advanced Algorithms and Data Structures - A different and a great way to introduce algorithms and data structures that can be used at work.
Algorithmic Puzzles - A very accessible illustration of algorithms in the forms of puzzles. No programming experience is required!
Standford CS166 - Standford CS166, a course in the design, analysis, and implementation of data structures.
Grokking Data Structures - Grokking Data Structures carefully guides you from the most basic data structures like arrays or linked lists all the way to powerful structures like graphs. It’s perfect for beginners.

Algorithm Analysis

Sedgewick & Flajolet. An Introduction to the Analysis of Algorithm - Am advanced complete survey, intended only for the mathematically matured reader.
McConnell. Analysis of Algorithms - A very accessible and brief book on algorithms analysis, with implemented code included.
Vrajitoru & Knight. Practical Analysis of Algorithms - A very accessible and brief book on algorithms analysis, with implemented code included.

Randomized Algorithms

Motwani & Raghavan. Randomized Algorithms - A standard classic book.
Mitzenmacher & Upfal. Probability and Computing: Randomization and Probabilistic Techniques in Algorithms and Data Analysis - Standard text for probability methods and their applications on randomized algorithms.

Cheat Sheets

Tech Interview Cheat Sheet
Princeton DS Cheat Sheet
CLRS in short
Rice university DS course in short
Useful Reddit thread
Algo Deck - An open-source collection of +200 algorithmic cards.

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 - A Japanese online judge from the University of Aizu, offering a wide range of algorithmic challenges.
Algo Muse - Research-based algorithmic problems.
AtCoder - Japanese programming contest website.
Baekjoon Online Judge - Korean Online Judge. 10000+ problems. Supports 60+ languages.
Beecrowd - The Largest Competitive Programming and Online Code Judgement Platform in Latin America.
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 - Practice programming and tackle 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 - Firecode.io 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 has problems based on Maths, Data Structures, Various Algorithm and also conducts Coding Competition.
HackerEarth - Practice algorithmic 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.
Paiza - A Japanese platform offering coding challenges and career preparation.
PKU JudgeOnline - Chinese Online Judge.
ProjectEuler - Mathematical problems that can be solved using algorithms (or just a pencil, depending on how much you already know).
Rosalind - A platform for learning bioinformatics and programming through problem-solving.
ShareCode.io - 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 regularly.
URI - Brazilian Online Judge. Not so many 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

Blogs

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

An awesome list for competitive programming! - Awesome blog for all the resources and list of books and algorithms.
Algorithms Weekly - A good blog by Petr Mitrichev, mainly in Java.
Sport of Programming - Informative blog for starting with the sport of programming.
Algorithms and Data Structures - For getting a deeper knowledge of algorithms and how to think in the right direction.
Algorithm Tutorials by Tanuj Khattar - Excellent blog by Tanuj Khattar. Covers tutorials on some interesting data structures along with example problems to solve.

Tools

Some tools that can help you in the learning of algorithms

interactive-coding-challenges - Interactive, test-driven coding challenges (algorithms and data structures).

Related Awesome Lists

Math - Freely available lecture notes on mathematics.
Theoretical Computer Science - The interdisciplinary of Mathematics and Computer Science, Distinguished by its emphasis on mathematical technique and rigour.

License

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

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