# Algorithms online problems

I'm trying in vain to find some online (classical) algorithms problems to deeply exercise "complexity" and maybe see (even try) mathematical demonstrations.

As far as I can see, the sites that I found (CodeChef, Project Euler) seem to be more programming oriented, even if I like the format and their challenge. That is, even when speed is somehow important, you cannot not know the exact complexities values for the algorithm (the lovely greek letters), maybe some demonstration of the efficiency of the solution.

An online course or a book is acceptable if it is more problems oriented. In my opinion, these are the kind of questions that a development top company should ask anyway.

• Since the answer is trivially algorithm-analysis, I don't quite see what you are getting at. (Be careful with your use of "complexity".) You might want to start at our reference questions on algorithms and asymptotics.
– Raphael
Nov 17 '14 at 15:19
• Have you looked at http://en.wikipedia.org/wiki/List_of_algorithms? Nov 17 '14 at 16:37
• @Raphael Sorry, I don't understand nothing from your comment Nov 17 '14 at 16:53
• There are algorithms on this page, which are widely used in the world right now - for example http://en.wikipedia.org/wiki/List_of_algorithms#Sequence_algorithms. Nov 17 '14 at 17:15
• @Liviu Practical problems are almost always all but impossible to analyse. Good luck. If you change your mind, feel free to follow the links I provide in my above comment.
– Raphael
Nov 17 '14 at 17:59

## 1 Answer

Cormen, Leiserson, Rivest and Stein's Introduction to Algorithms (MIT Press, 3rd edition, 2009) is a good book for understanding and solving time complexity and correctness of algorithms mathematically.

• Still, the post does not answer the question (which requests problems found on the web), however ill-advised it may be.
– Raphael
Nov 18 '14 at 13:33
• @Raphael I'am wrong if he is asking question for competitive programming. Nov 18 '14 at 15:36
• @Raphael The question says, "An online course or a book is acceptable if it is more problems oriented." Nov 18 '14 at 16:12
• @DavidRicherby Hm, I read "online (course | book)". I agree that "(online course) | book" is a plausible parse.
– Raphael
Nov 19 '14 at 10:59