<p>As a self-taught computer programmer, I'm often at a loss to estimate the O() value for a particular operation.  Yeah, I know off the top of my head most of the important ones, like for the major sorts and searches, but I don't know how to calculate one when something new comes along, unless it's blindingly obvious.  Is there a good web site or text that explains how to do that?  Heck, I don't even know what computer scientists call it, so I can't google it.</p>

[{'answer_id': 62734, 'author': 'Tim Howland', 'author_id': 4276, 'author_profile': 'https://Stackoverflow.com/users/4276', 'pm_score': 3, 'selected': False, 'text': '<p>It\'s called <a href="http://en.wikipedia.org/wiki/Big_O_notation" rel="nofollow noreferrer">Big O Notation</a>, and it\'s used in <a href="http://en.wikipedia.org/wiki/Computational_complexity_theory" rel="nofollow noreferrer">Computational Complexity Theory</a>.</p>\n\n<p>The wikipedia articles are a pretty good starting point, as are the bibliography at the bottom of the page.</p>\n'}, {'answer_id': 62746, 'author': 'Bill the Lizard', 'author_id': 1288, 'author_profile': 'https://Stackoverflow.com/users/1288', 'pm_score': 2, 'selected': False, 'text': '<p><a href="http://mitpress.mit.edu/algorithms/" rel="nofollow noreferrer">Introduction to Algorithms</a> is the standard text used at most universities.  I\'ve used it and can recommend those chapters on order analysis.  I\'d start with the articles in Tim Howland\'s answer, though.</p>\n'}, {'answer_id': 62759, 'author': 'ivan', 'author_id': 7039, 'author_profile': 'https://Stackoverflow.com/users/7039', 'pm_score': 1, 'selected': False, 'text': '<p>It is called algorithm analysis and is a science in itself. Take a look at some of the books <a href="http://4storing.biz/f/3wv:24763a50" rel="nofollow noreferrer">here</a></p>\n'}, {'answer_id': 62894, 'author': 'eladv', 'author_id': 7314, 'author_profile': 'https://Stackoverflow.com/users/7314', 'pm_score': 3, 'selected': True, 'text': '<p>If you really want to learn this topic, then you probably need a standard theory/algorithms textbook. I don\'t know of any website that can actually teach you complexity analysis ("complexity" or "time complexity" is how you call those O() values; you might also want to google for "analysis of algorithms" or "introduction to algorithms" or such).</p>\n\n<p>But before that -- a free option. There are slides from a course given by Erik Demaine and Charles Leiserson in MIT, that are free and look great. I would definitely try to read them and see if that works for you. They are <a href="http://ocw.mit.edu/OcwWeb/Electrical-Engineering-and-Computer-Science/6-046JFall-2005/LectureNotes/" rel="nofollow noreferrer">here</a>.</p>\n\n<p>Now, textbooks:</p>\n\n<p>The classical choice for a textbook is Cormen et al\'s book <a href="https://rads.stackoverflow.com/amzn/click/com/0262032937" rel="nofollow noreferrer" rel="nofollow noreferrer">Introduction to Algorithms</a> (there might be a cheap version available to buy <a href="http://www.fetchbook.info/fwd_description/search_9780262032933.html" rel="nofollow noreferrer">here</a> and I remember seeing a free (possibly illegal) version online, but I don\'t remember where).</p>\n\n<p>A more recent and modern-style book, which is IMO more fun to read and a better choice, is Kleinberg and Tardos\' <a href="https://rads.stackoverflow.com/amzn/click/com/0321295358" rel="nofollow noreferrer" rel="nofollow noreferrer">Algorithm Design</a>.</p>\n\n<p>Here are some websites with information (I got these by googling "algorithm analysis lecture notes" without the quotes):</p>\n\n<ul>\n<li><a href="http://www.personal.kent.edu/~rmuhamma/Algorithms/algorithm.html" rel="nofollow noreferrer">Algorithms Lecture Notes</a></li>\n<li><a href="http://www.cs.sunysb.edu/~algorith/lectures-good/index.html" rel="nofollow noreferrer">Lecture notes by Steve Skiena</a></li>\n</ul>\n\n<p>The above is written by a computer science theorist. So programmers or other practical people might have some different opinions.</p>\n'}, {'answer_id': 70686, 'author': 'ivan', 'author_id': 7039, 'author_profile': 'https://Stackoverflow.com/users/7039', 'pm_score': 0, 'selected': False, 'text': "<blockquote>\n  <p><em>Your links takes me to a site in</em>\n  <em>Russian that seems to want a userid</em>\n  <em>and password. Legitimate mistake, or</em>\n  <em>troll? Paul Tomblin</em></p>\n</blockquote>\n\n<p>The site is in Bulgarian and you shouldn't need a password to access the list of files I linked to and download some of them. Unless of course there is an access restiction for IPs from outside Bulgaria, which I really don't know.</p>\n\n<p>Sorry, I don't know how to make a comment.</p>\n"}]
['https://Stackoverflow.com/questions/62702', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/3333/']