Search Results

• Most efficient method to query a Young Tableau

- by Matthieu M.
A Young Tableau is a 2D matrix A of dimensions M*N such that: i,j in [0,M)x[0,N): for each p in (i,M), A[i,j] <= A[p,j] for each q in (j,N), A[i,j] <= A[i,q] That is, it's sorted row-wise and column-wise. Since it may contain less than M*N numbers, the bottom-right values might be represented either as missing or using (in algorithm theory) infinity to denote their absence. Now the (elementary) question: how to check if a given number is contained in the Young Tableau ? Well, it's trivial to produce an algorithm in O(M*N) time of course, but what's interesting is that it is very easy to provide an algorithm in O(M+N) time: Bottom-Left search: Let x be the number we look for, initialize i,j as M-1, 0 (bottom left corner) If x == A[i,j], return true If x < A[i,j], then if i is 0, return false else decrement i and go to 2. Else, if j is N-1, return false else increment j This algorithm does not make more than M+N moves. The correctness is left as an exercise. It is possible though to obtain a better asymptotic runtime. Pivot Search: Let x be the number we look for, initialize i,j as floor(M/2), floor(N/2) If x == A[i,j], return true If x < A[i,j], search (recursively) in A[0:i-1, 0:j-1], A[i:M-1, 0:j-1] and A[0:i-1, j:N-1] Else search (recursively) in A[i+1:M-1, 0:j], A[i+1:M-1, j+1:N-1] and A[0:i, j+1:N-1] This algorithm proceed by discarding one of the 4 quadrants at each iteration and running recursively on the 3 left (divide and conquer), the master theorem yields a complexity of O((N+M)**(log 3 / log 4)) which is better asymptotically. However, this is only a big-O estimation... So, here are the questions: Do you know (or can think of) an algorithm with a better asymptotical runtime ? Like introsort prove, sometimes it's worth switching algorithms depending on the input size or input topology... do you think it would be possible here ? For 2., I am notably thinking that for small size inputs, the bottom-left search should be faster because of its O(1) space requirement / lower constant term.

• 2011 PASS Board Applicants: Rob Farley

- by andyleonard
Introduction I am interviewing 2011 PASS Board Nominee Applicants. As listed on the PASS Board Elections site the applicants are: Rob Farley Geoff Hiten Adam Jorgensen Denise McInerney Sri Sridharan Kendal Van Dyke I'm asking everyone the same questions and blogging the responses in the order received. Rob Farley is first up: Interview With Rob Farley 1. What's your day job? I run LobsterPot Solutions out of Adelaide, Australia. We're a SQL & BI consultancy, and were the first Microsoft Partner...(read more)

• @CodeStock 2012 Review: Rob Gillen ( @argodev ) - Anatomy of a Buffer Overflow Attack

Anatomy of a Buffer Overflow AttackSpeaker: Rob GillenTwitter: @argodevBlog: rob.gillenfamily.net Honestly, this talk was over my head due to my lack of knowledge of low level programming, and I think that most of the other attendees would agree. However I did get the basic concepts that we was trying to get across. Fortunately most high level programming languages handle most of the low level concerns regarding preventing buffer overflow attacks. What I got from this talk was to validate all input data from external sources.

• @CodeStock 2012 Review: Rob Gillen ( @argodev ) - Anatomy of a Buffer Overflow Attack

Anatomy of a Buffer Overflow AttackSpeaker: Rob GillenTwitter: @argodevBlog: rob.gillenfamily.net Honestly, this talk was over my head due to my lack of knowledge of low level programming, and I think that most of the other attendees would agree. However I did get the basic concepts that we was trying to get across. Fortunately most high level programming languages handle most of the low level concerns regarding preventing buffer overflow attacks. What I got from this talk was to validate all input data from external sources.

• Why aren't young programmers interested in mainframes?

- by temptar
A key issue with mainframes is that the cohort of supporting programmers is dwindling. While normally this wouldn't be a problem in that a falling supply of programmers would be offset by an increasing amount of salary those causing a rising supply of programmers via the law of supply and demand, I'm not sure this is really happening for mainframes. While they still form critical infrastructure for many businesses, the simple fact is there isn't an adequate number of young programmers coming up along to keep the support population populated. Why is this? What makes mainframes unattractive to young programmers?

• Install of AppFabric RC stops AppFabric Monitoring (some traps for young players)

I uninstalled AppFabric Beta 2 and installed AppFabric RC. The AppFabricEventCollection Service is started (runs under Local Service which is a dbo_owner on the Monitoring Database to prove this wasn’t the issue). The SQLServerAgent Service is started. Nothing is being written to the Monitoring DB Staging Table and thus nothing is being written to the Event tables or seen in the AppFabric Dashboard. Nothing has been written to the following event logs     - Microsoft-Windows-Application Server-System Services\Admin     - Microsoft-Windows-Application Server-System Services\Operational The Microsoft-Windows-Application Server-System Services\Debug event log is not shown in the event viewer. The WCF configuration appears fine the connection string to the Monitoring DB is correct. Monitoring is set to “Trouble Shooting” and no errors are shown on the “Configure WCF and WF for Application” dialog. So the problem seems to lie with either AppFabric which writes to the event log or the AppFabricEventCollection Service. I thought I was flummoxed... However one of my colleagues said have you checked the etwProviderId? I was using a config which was created under AppFabric  Beta 2 which had a different etwProviderId. So I deleted the following section and all other references to AppFabric monitoring from the web.config and then recreated them using IIS the “Configure WCF and WF for Application” dialog and set the level to TroubleShooting.         <diagnostics etwProviderId="6b44a7ff-9db4-4723-b8cf-1b584bf1591b">             <endToEndTracing propagateActivity="true" messageFlowTracing="true" />         </diagnostics>   I then called a service to create some log entries. Still nothing was written to the Monitoring DB Staging Table... I checked the Microsoft-Windows-Application Server-System Services\Admin event log. It had the following entry... Configuration error. Please see the details to correct the problem. \rDetailed information:\r Filename: \\?\C:\Users\xxx\Documents\dotnetdev\Frameworks\SOA\xxx.SOA.Framework\xxx.SOA.Framework.MockServices\SimpleServiceParent\web.config Error: Cannot read configuration file due to insufficient permissions    System.UnauthorizedAccessException: Filename: \\?\C:\Users\xxx\Documents\dotnetdev\Frameworks\SOA\xxx.SOA.Framework\IAG.SOA.Framework.MockServices\SimpleServiceParent\web.config Error: Cannot read configuration file due to insufficient permissions   And guess who the user was... Local Service yes yes I should have used a better User in the AppFabric RC setup to run the AppFabricEventCollection Service under! So I changed the user to a more appropriate one and removed Local Service as a DBO and hay presto!

• NDC2010: Rob Conery I cant hear you, there is an ORM in my ear

In this session Rob Conery tried to show of the new Shiny toy NoSQL in as many forms as possible, discussing the pros and and some cons. He based much of the talk on his experiences with building TekPub and the requirements they had around that. He tried to illustrate that this wasnt a magical [...]...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

• Edinburgh this Thurs (25th) - Rob Carrol talks about how to build a high performance, scalable repor

- by tonyrogerson
Scottish Area SQL Server User Group Meeting, Edinburgh - Thursday 25th March An evening of SQL Server 2008 Reporting Services Scalability and Performance with Rob Carrol, see how to build a high performance, scalable reporting platform and the tuning techniques required to ensure that report performance remains optimal as your platform grows. Pizza and drinks will be provided! Register at http://www.sqlserverfaq.com/events/221/SQL-Server-2008-Reporting-Services-Scalability-and-Performance.aspx...(read more)

• SQLPeople Interviews - Jamie Thomson and Rob Farley

- by andyleonard
Introduction Late last year I announced an exciting new endeavor called SQLPeople . At the end of 2010 I announced the 2010 SQLPeople Person of the Year . Interviews I'm pleased to announce the first two interviews have been posted. They are with my friend and co-SSIS-professional Jamie Thomson and Rob Farley , someone I had the pleasure of meeting in person at the PASS Summit 2010. I plan to post two or three interviews each week for the forseeable future. Conclusion SQLPeople is just one of the...(read more)

• Useful certifications for a young programmer

- by Alain
As @Paddyslacker elegantly stated in Are certifications worth it? The main purpose of certifications is to make money for the certifying body. I am a fairly young developer, with only an undergraduate degree, and my job is (graciously) offering to sponsor some professional development of my choice (provided it can be argued that it will contribute to the quality of work I do for them). A search online offers a slew of (mostly worthless) certifications one can attain. I'm wondering if there are any that are actually recognized in the (North American) industry as an asset. My local university promoted CIPS (I.S.P., ITCP) at the time I was graduating, but for all I can tell it's just the one that happened to get its foot in the door. It's certainly money grubbing - with a \$205 a year fee. So are there any such certifications that provide useful credentials? To better define 'useful' - would it benefit full time developers, or is it only something worth while to the self-employed? Would any certifications lead me to being considered for higher wages, or can that only be achieved with more experience and an higher-level degree?

• What Contents in a Young Programmer's Personal Website

- by DotNetStudent
I recently stumbled upon this question in which the contents a professional programmer's website should have were discussed and I agree with most of the answers there. However, I am by no means a professional programmer (just came out from university) and so I am a bit lost in what concerns the contents I should provide in the personal website I am designing for myself now. I do have a pretty nice job at a fast-growing software company but I would really like to present myself to the outside world in a nice but humble manner since my curriculum is by no means a long one. Any ideas?

• Perfect Techniques For Those Young Students in Practicing Piano

Knowing the perfect and appropriate strategies are very important in kids piano. Acquiring perfect learning techniques over years of coaching experience is the reason that creates perfect teachers. Y... [Author: Scheygen Smith - Computers and Internet - March 21, 2010]

• Is Application Development a Young Person's Game?

Both youth and experience offer advantages.

• Is Application Development a Young Person's Game?

Both youth and experience offer advantages.

• Young C++ student lacking direction

- by ephaitch
I was hoping for some direction or guidance regarding my C++ learning experience. I have now read two books, from cover to cover, twice. The first was Ivor Horton's Beginning Visual C++ 2010 and Starting out with C++ Early Objects (7th Edition). At this point and after several months I feel like all I know how to do in C++ is create a basic class, define some methods, use the STL, and read and write info to and from the console buffer (cin/cout). But simple things like saving data to a file, reading from a file, printing, connecting to an FTP site, doing some basic graphic manipulation on the screen (not even DirectX/OpenGL), and so-on I can't do or don't even know where to start. I feel I still haven't learned C++ thoroughly. I think you guys get where I'm going with this. I tried downloading SFML and compiling it in Visual C++ 2010 Professional. After quite a bit of time, I got it, but then I was lost. I followed the tutorials and one didn't work. I kept getting an error regarding a missing symbol and after an hour or so on Google, I couldn't figure it out. Can anyone point me in a direction of where one goes from here? I would imagine others have been at this point sometime during their early days.

• Am I too young to burn out?

- by Steve McMesse
I feel like I have burned out, even though I am only out of college for 5 years. For the first 3 years of my career, things were going awesome. I was never anything special in school, but I felt special at my company. Looking back, I could tell that I made all the right moves: I actively tried to improve myself daily. I made a point of helping anyone I could. I made a point (and read books about) being a good team member. I had fun. After 3 years in a row as being rated as a top employee, I converted that political capital into choosing to work on an interesting, glamorous project with only 2 developers: me and a highly respected senior technical leader. I worked HARD on that project, and it came out a huge success. High in quality, low in bugs, no delays, etc. The senior tech lead got a major promotion and a GIGANTIC bonus. I got nothing. I was so disappointed that I just stopped caring. Over the last year, I have just kind of floated. During my first 4 years I felt energized after a 10 hour day. Now I can barely be bothered to work 6 hours a day. Any advice? I don't even know what I'm asking. I am just hoping smart people see this and drop me a few pieces of wisdom.

• Looking for suggestions: becoming a hireable, young programmer [closed]

- by Dan
I am a 17 year old Java programmer that has filled the last year with learning all of the ins and outs of Java - Using Eclipse, and the help of a friend of the family (a Java programming architect for some company), I have learned everything from serializing objects, basic networking, generics, reflection, multi-threading, code optimization and efficiency & some concurrency safety - built my own proxy class, and nowadays, I answer questions on Project Euler. I am seeking some suggestions though on where I go next, or where I go from here to get a job in programming. I dedicate at least an hour every day to coding, sometimes literally, the entire day, and I really have come to love the process. I just started reading Effective Java (v2), and learning Scala (as I see often, possibly the Java replacement) I will be going to college for Computer Science next year - and taking AP computer science this year (however, I took a practice exam and got an 87, only need a 60to70 to pass, so no need to study for it too much) -- I was wondering if getting the SE 7 OCA and OCP would help me in trying to get a programming job. I looked around and most people have said online that an OCA/OCP are practically useless, but, at my age do they make me any more credible? More or less, what would you recommend to get a job in programming these days - or distinguish yourself from the crowd? I have enough time and dedication to learn another language, or anything really. Thank you very much.

• Interviewing - convincing young interviewers that my experience matters [closed]

- by ritu
As requested, I split this question from a two part question I asked at http://stackoverflow.com/questions/2482071/modern-web-development-general-question My question is how do i convince the young programmers who interview me that my years of system programming experience, MFC, Win32 programming are still relevant and I should not be automatically rejected because I don't know the differences between Drupal and <pick your technology>. It seems like I can ask a dozen question that these guys won't be able to answer but somehow because I don't know the latest fad counts against me. I do read, but if you don't use what you read in your daily work, you will never have expert knowledge of it. So bottom line: is the only way for me to take a .NET or Java job is for me to start at the bottom all over?

• Young people using Emacs?

- by bigmonachus
I am a college student that has fallen in love with Emacs. I have used IDEs in the past, and although features like Intellisense made the switch to Emacs very hard, I now think that Emacs is much more powerful, and features like Intellisense can be pretty closely matched by various modes depending on language (and I am not referring to M-/). I am happily writing Elisp code for everything that I need that isn't provided by modes or by Emacs itself and I love the way that it adapts and molds to my needs. However, I do think that its main disadvantage is the fact that it has a pretty steep learning curve and that most new programmers will not even begin to learn it out of many common misconceptions. So, I want to know the opinions of young people (or any person who didn't start using Emacs before there were IDEs) that are Emacs users. Just to get some reassurance that Emacs is not dead within our Eclipse-loving generation =). (Opinions of users of any other highly extensible editor like Jedit are also welcome)

• Programming as a minor

- by Tomas Cokis
Hello Everyone! I've never asked a question here at programmers, and for reasons which will become obvious later I've never answered one here, but I do poke around in short bursts. Anyway, I'm 15 right now, and I've been programming in C++ for 4 years, just working on my own projects that are aim so high as to never be finished. I've been working on a single project for the last year, and every 3 months, I add a new system into it. It might be a value tabling directory enabled log system, or a render system, or a class to load up xml files, whatever it is, I don't mind too much that the overall project (a 3d engine) isn't ever going to get finished, I just get some satisfaction from getting what I have done building and running. I don't know what I want to do when I grow up, although I suspect I'll go into some form of engineering, but I was interested in knowing if I do choose to go into a career as a developer, what kind of material I could look at to push myself up and get myself experience that might help my career later. I'm not talking about books in particular, I'm more interested in subjects areas that will get me access to good job opportunities, or that will give me a hand-up if I do computer science and software related courses at uni. One of the things I was thinking of doing was designing some of the logic gate components of a small computer - which I started briefly over the holidays, working out integer addition, subtraction and multiplication. That kind of stuff interests me, but is it really useful - or more useful then just more programming? But anyway, Any advice? Should I continue on my perpetual 3d engine? Are there any other projects or particular accomplishments that would help my education? Perhaps I should mention that I live in Perth, Australia, so local software companies are likely to be more scarce then usual.

• Asp.Net MVC - Rob Conery's LazyList - Count() or Count

I'm trying to create an html table for order logs for customers. A customer is defined as (I've left out a lot of stuff): public class Customer { public LazyList<Order> Orders { get; set; } } The LazyList is set when fetching a Customer: public Customer GetCustomer(int custID) { Customer c = ... c.Orders = new LazyList<Order>(_repository.GetOrders().ByOrderID(custID)); return c; } The order log model: public class OrderLogTableModel { public OrderLogTableModel(LazyList<Order> orders) { Orders = orders; Page = 0; PageSize = 25; } public LazyList<Order> Orders { get; set; } public int Page { get; set; } public int PageSize { get; set; } } and I pass in the customer.Orders after loading a customer. Now the log i'm trying to make, looks something like: <table> <tbody> <% int rowCount = ViewData.Model.Orders.Count(); int innerRows = rowCount - (ViewData.Model.Page * ViewData.Model.PageSize); foreach (Order order in ViewData.Model.Orders.OrderByDescending(x => x.StartDateTime) .Take(innerRows).OrderBy(x => x.StartDateTime) .Take(ViewData.Model.PageSize)) { %> <tr> <td> <%= order.ID %> </td> </tr> <% } %> </tbody> </table> Which works fine. But the problem is evaluating ViewData.Model.Orders.Count() literally takes about 10 minutes. I've tried with the ViewData.Model.Orders.Count property instead, and the results are the same - takes forever. I've also tried calling _repository.GetOrders().ByCustomerID(custID).Count() directly from the view and that executes perfectly within a few ms. Can anybody see any reason why using the LazyList to get a simple count would take so long? It seems like its trying to iterate through the list when getting a simple count.

• Advice for young software professional ?

I recently graduated from college and joined a big reputed software company. I am wondering how would you differentiate yourself among thousands of other competitive & intelligent software engineers and programmers. I am not discounting hard work here. Rather, I would like to know how to go about the job, what things to look out for, opportunities which might about in future or advice in general.