Websites you should use to learn classic algorithms
- A Visual Guide to Graph Traversal Algorithms – Interactive visualisations for learning how graph traversal algorithms work
- Algomation – A didactic, animated, exposition of algorithms.
- 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.
- 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 ?!!
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 ministred 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.
- 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 vidoes on various computer science subjects.Account terminated due to violations of Youtube Policies.
The most highly regarded books to learn algorithms
- Algorithm Design – Pretty straight-forward.
- Algorithms – Problems explained with Java, OO good practices, visualizations, and free online resources.
- 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
- Algorithms and Data Structures in Action – A different and a great way to introduce algorithms and data structures that can be used at work.
- The Technical Interview Cheat Sheet
- Princeton DS Cheat Sheet
- CLRS in short
- Rice university DS couse in short
- Useful Reddit thread
- Algo Deck – An open-source collection of +200 algorithmic cards.
Implementations of the most classic algorithms in a wide variety of programming languages
- Language agnostic
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.
- 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 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.
- 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.
- 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).
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 – Really informative blog for starting with the sport of programming.
- Algorithms and Data Structures – For getting deeper knowledge of algorithms and how to think in right direction.
Some tools that can help you in the learning of algorithms
- interactive-coding-challenges – Interactive, test-driven coding challenges (algorithms and data structures).