We like to think that a memory access is fast and constant, but on modern architectures/OSes, that's not necessarily true. Consider the following C code: int i = 34; int *p = &i; // do something that may or may not involve i and p {...} // 3 days later: *p = 643; What is the estimated cost of this last assignment in CPU instructi...
What is the shortest hash that can be obtained and why? What happens if you try to achieve a shorter one, is there a fixed limit or does it depend on the length of the hashed data and why? ...
Transparent persistence allows you to use regular objects instead of a database. The objects are automatically read from and written to disk. Examples of such systems are Gemstone and Rucksack (for common lisp). Simplified version of what they do: if you access foo.bar and bar is not in memory, it gets loaded from disk. If you do foo.ba...
I have a toroidal-ish Euclidean-ish map. That is the surface is a flat, Euclidean rectangle, but when a point moves to the right boundary, it will appear at the left boundary (at the same y value), given by x_new = x_old % width Basically, points are plotted based on: * see edit (x_new, y_new) = ( x_old % width, y_old % height) Thin...
Hi, I have been using Qt 4.5 and so do C++. I have been told that it's a standard practice to maintain the length of each statement in the application to 80 characters. Even in Qt creator we can make a right border visible so that we can know whether we are crossing the 80 characters limit. But my question is, Is it really a standard ...
Hi Guys, I like to think that recently I have moved from complete beginner to beginner. It has been a hard road and one on which I took many wrong turns. Very rarely in any profession is there a place where so many rock stars gather, this is something I would like to take advantage of. What I would like to ask is what are your perls of...
I've got the following regex that was working perfectly until a new situation arose ^.*[?&]U(?:RL)?=(?<URL>.*)$ Basically, it's used against URLs, to grab EVERYTHING after the U=, or URL= and return it in the URL match So, for the following http://localhost?a=b&u=http://otherhost?foo=bar URL = http://otherhost?foo=bar Unfortun...
I'm using an LL(k) EBNF grammar to parse a character stream. I need three different types of tokens: CHARACTERS letter = 'A'..'Z' + 'a'..'z' . digit = "0123456789" . messageChar = '\u0020'..'\u007e' - ' ' - '(' - ')' . TOKENS num = ['-'] digit { digit } [ '.' digit { digit } ] . ident = letter { letter | digit | '_' } . ...
There is this xkcd comic: I recently saw a version with "probability protocol is good" and a quote from the HTTP RFC (I believe). But I can't seem to find it anymore. Can someone help? (I need this to convince some of my co-workers that they're doing the design for a network protocol we're building wrong, so this question is programm...
Since naming is a so important thing in programming, I would like to start a thread for giving help to all those that have same problems as I sometimes. Rules: Set a post with the description of the form||control||class or whatever you need to find a good name for. Get name hints in the answers. ...
It's a pretty normal binary tree, except for the fact that one of the nodes may be empty. I'd like to find a way to output it in a horizontal way (that is, the root node is on the left and expands to the right). I've had some experience expanding trees vertically (root node at the top, expanding downwards), but I'm not sure where to st...
Hi, I came across this problem in an interview website. The problem asks for efficiently implement three stacks in a single array, such that no stack overflows until there is no space left in the entire array space. For implementing 2 stacks in an array, it's pretty obvious: 1st stack grows from LEFT to RIGHT, and 2nd stack grows fro...
I'm just trying to understand the Templating(system). If you use MVC in your web application then you don't need to use something like Smarty(template engine) as you are already separating application code from presentation code anyway by using MVC right? please correct me? So am i correct in thinking it's MVC OR Templating or do you us...
I have legacy win.forms application written in pretty straightforward approach where forms communicate with DAL on UI events. For example there are textboxes: login/password, button - "Login" and a click-handler where business logic is implemented (DAL is asked to get user by id/password, if not null - than show next screen, if null - sh...
I have commands classes that implement ICommand { Execute } interface. Several commands have duplicate pieces of code. I have several options how to DRY: Create static helper class(es) and move duplicate code there Create commands inheritance with protected helper methods What would you suggest and why? ADDED Thank you everyone w...
So you have a long running process, perhaps with a progress bar, and you want a text estimate of the remaining time, eg: "5 minutes remaining" "30 seconds remaining" etc. If you don't actually want to report clock time (due to accuracy or resolution or update-rate issues) but want to stick to the text summary, what is the correct paradi...
what's the General difference between structural program and object oriented program?? what OOP offers?? thank you all ...
From what I understand, I need to use WADL to describe a RESTful web service. Still, I have read many answers in relevant posts, where users are strongly opposed the use of WADL. What are the disadvantages of WADL? Is there any alternative solution? ...
This isn't a question about code, but it's programming related. We have a web app that's ready for beta testing. Has anyone noticed any difference between open beta vs. closed beta in terms of the quality or quantity of feedback the testers give or any other factors? ...
I would like to generate a random string (or a series of random strings, repetitions allowed) of length between 1 and n characters from some (finite) alphabet. Each string should be equally likely (in other words, the strings should be uniformly distributed). The uniformity requirement means that an algorithm like this doesn't work: al...