@Gilles: I'm confused. You rewrote my answer -- whereas yours was interesting -- just with a nice drawing? We could have managed a discussion if mine was not clear, don't you think?
I have an assignment where I need to make use a binary search tree and alter it to self order itself such that items that are accessed the most (have a higher priority) are at the top of the tree, the root being the most accessed node.
The professor gave me the BST and node struct to work with, ...
Are there any sites like Stack Overflow where we can ask computer science and more theoretical questions? What do you guys/gals use other than this site?
EDIT:
Even though I really didn't get satisfactory answers, I am closing the bounty. I have been using comp.lang.* and the guys there have be...
What is the right site on the Stack Exchange network for computer science questions?
None of the answers I can think of are remotely satisfying:
Stack Overflow: Even if CS questions are acceptable (some get closed, which I think shows they're not getting the right audience), where is the exper...
Doing the exercise, posting the answer with detailed relations and explanations, to find hours later my answer rewritten (I thought). But yes, this is a classical example.
@Gilles so this does not matter, sorry for the disturbance.
@MichaelMrozek although one could argue that by editing the question, you save the potential reader of reading the entire debate only to realize that it's a pointless one
While discussing some intro level topics today, including the use of genetic algorithms; I was told that research has really slowed in this field. The reason given was that most people are focusing on machine learning and data mining. Is this accurate, and if so why is there this trend towards th...
What are some good online resources that will help me better understand BigO notation, running time & invariants?
I'm looking for lectures, interactive examples if possible.
You have 1 coin. You may flip it as many times as you want.
You want to generate random number r such that $a \leq r \leq b$ where r,a,b $\in \mathbb{Z}^+$.
Distribution of the numbers should be uniform.
Its easy if $b -a = 2^n$.
r = a + binary2dec(flip n times write 0 for heads and 1 for...
should questions like BigO, Running Time, Invariants - Learning Resources be tagged with resource-request ?
This might apply also to many of the big-list questions.
Suppose I have two strings. Call them A and B. Neither string has any repeated characters.
How can I find the shortest sequence of insert, move, and delete operation that turns A into B, where:
insert(char, offset) inserts char at the given offset in the string
move(from_offset, to_offset) mov...
Now that the site is accessible publicly we should try to promote it. This post is for discussing ideas about promotion.
How can we promote the site further?
The list is as follows:
Are questions about [subject] on or off topic?
What should our FAQ contain?
How should we tag questions about {subject}?
What’s the “elevator pitch” for our site?
What should our logo and site design look like?
Who should the moderators be?
How do we promote our site?
...
Suppose we have a balanced binary tree, which represents a recursive partitioning of a set of $N$ points into nested subsets. Each node of the tree represents a subset, with the following properties: subsets represented by two children nodes of the same parent are disjoint, and their union is eq...
I understand the theory behind Bayesian networks, and am wondering what it takes to build one in practice. Let's say for this example, that I have a Bayesian (directed) network of 100 discrete random variables; each variable can take one of up to 10 values.
Do I store all the nodes in a DAG, and...
I believe I have a reasonable grasp of complexities like O(1), O(n) and O(n2).
In terms of a list, O(1) is a constant lookup, so it's just getting the head of the list.
O(n) is where I'd walk the entire list, and O(n2) is walking the list once for each element in the list.
Is there a similar in...
Simply put, if one were to build a quantum computing device with the power of, say, 20 qubits, could the processing power by said computer be used to make any kind of modern hashing algorithm useless?
Would it even be possible to harness the power of quantum computing in a traditional computing...
we r created collage database in which we have attendance table the colomn in this tables are subj id,present no,absent no,date,time etc in colomn present no and absent no we put the roll nos seprated by comma like in present no colomn 1,2,3,4,5,6,7 and so on and we want result like from date 2 t...
I know that since ~2004, Moore's law stopped working for CPU clock speed.
I'm looking for a graph showing this, but am unable to find it: most charts out there show the transistor count or the capacity per year.
Where can I find some data showing the CPU frequency of computers (anything is fine,...
My company has a software and I want people to install crucial upgrades. Because there is a bug which can be exploited by hackers crackers or virus writers. And within hours everything will be compromised.
I can host upgrades on a server send out notifications let people download and install t...
The list is as follows:
Are questions about [subject] on or off topic?
What should our FAQ contain?
How should we tag questions about {subject}?
What’s the “elevator pitch” for our site?
What should our logo and site design look like?
Who should the moderators be?
How do we promote our site?
...
We certainly don't want to discourage applied topics. Otherwise this will just become CSTheory Jr, which is not what we want.
Plenty of people are doing systems-building style computer science research. Does anyone know how they would describe what they do as science? We don't want to exclude such people, at least when they are asking questions about the science aspects of what they do.
Regarding the ongoing discussion, I think whatever wants to be ontopic should either refer to "standard material" or include some level of abstraction and/or generalisation.
I don't really see that it's subjective, I'm afraid. The more I think about the question, the more I like about it. But I'm supposed to be preparing for a lecture, not chatting ...
This is a puzzle about measuring network latency that I created. I believe the solution is that it's impossible, but friends disagree. I'm looking for convincing explanations either way. (Though it is posed as a puzzle I think it fits on this web site because of its applicability to the design an...
@PratikDeoghare There is research about viruses; that does not mean your question is a scientific one per se. There is theory about programming languages, but a programming question is not scientific.
What Raphael said - your first alternative you pose is a user interaction issue, the second a legal issue and the question you end with seems like an IT question to me
@Raphael @Alex I am sorry it got interpreted that way. First is common practice, second is attempt to ridicule windows and third is attempt to show how viruses could help. I must learn to write well.
Regarding the scope of our site, how about this: "questions to which the answers have a theoretical framework" - it's not a good criterion for the questioners (who don't know the answers), so we may need an equivalent criterion for that, but at least I think it captures the scope
Or maybe even 'theoretic or scientific framework', to not exclude the question about Moore's law earlier
I don't know; I don't think asking for a basic CS course is a good question for SE. It is a fair question, it is just not suited for the platform. It is either unanswerable or a "list question".
@Gilles I don't understand your retagging for cs.stackexchange.com/q/570/157. "probability-theory" is a field of math, not CS. The question is about algorithm that deals with randomness - i think "randomized algorithms" is more proper. Also, generally the "randomness" tag is more adequate than "random" to algorithm that utilize randomness and random-number-generators (which could be a proper tag for this case as well).
@RanG I phrased that badle. I am completely fine with the question on cs.SE as it is natural to have in the context of CS. But underneath, it is a math question.
@RanG That is not the question here. The question is "How do I get a x-distributed r.v. X if I have i.i.d y-distributed ones?" -- typical stochastics question
This is a follow up to my earlier questions on coinduction and bisimulation.
Recalling, a labelled transition system is a triple $(S,\Lambda,\to)$, where $S$ is a set of states, $\Lambda$ is a set of labels, and $\to\subseteq S\times\Lambda\times S$ is a ternary relation., where $(p,\alpha,q)\in...
How to improve the worst case scenario for a depth first search on an euler graph, starting at some point and ending at that same point.
I need to do the whole search but it ain't fast enough for large amounts of data, I've tried bidirectional but I can't really keep the result numericly ordere...
Assume I have two formulae $\Phi$ and $\Psi$ (over the same set of atomic propositions $AP$) in CTL. We have that $\Phi \equiv \Psi$ iff $Sat_{TS}(\Phi) = Sat_{TS}(\Psi)$ for all transition systems $TS$ over $AP$.
Given that there are infinitely many transition systems, it's impossible to check ...
A common misconception, imho. While there are people in CS who deal with specific instances of some concepts (e.g. a certain programming language or database), most of the time that is to try out stuff or create proof-of-concept implementations.
The majority busies themselved with finding general problems and solutions.
(I am only a Master student myself, so take that with a grain of salt)
there are regional differences, though. Afaik, CS in Scandinavia and even US is far more applied than e.g. in Germany or France. And don't even mention India.
anyway, a question "How do I write a virus that exploits Windows 7 vulnerability X?" is certainly off-topic here. "What are common weaknesses of operating systems?" may be ok. The question we are talking about is in a grey area. See also the ensuing discussion above (here in chat).
How to improve the worst case scenario for a depth first search on an euler graph, starting at some point and ending at that same point?
I need to do the whole search but it is not fast enough for large amounts of data. I have tried bidirectional search but I can not keep the result numerically ...
The standard algorithm runs in linear time, so he has to deal with constant factors, and that means we'll have to see his code, at which point the question may be better suited for SO?
@Jetti I have fun with algorithms and data structures. In the past, I have been looking into some aspects of TCS applied to bioinformatics, but now I am mostly interested in parallel algorithms.
On a side note, the solution for this question (cs.stackexchange.com/questions/555/…) turned out to be quite a bit more involved than I originally thought
I was given the question
Where does the following language fit in the Chomsky hierarchy?
Nonnegative solutions (x,y) to the diophantine equation $3x-y=1$.
I understand languages like $L = \{ 0^n1^n \mid n \ge 1\}$, but this language confuses me. What do the words in the language look ...
I have the following language
I am trying to determine which chomsky language class it fits into. I can see how it could be made using a context-sensitive grammar so I know it is atleast context-sensitive. It seems like it wouldn't be possible to make with a context-free grammar, but I'm havin...
A directed graph is said to be unipathic if for any two vertices $u$ and $v$ in
the graph $G$, there is at most one simple path from $u$ to $v$.
Suppose I am given a unipathic graph $G$ such that each edge has a positive or negative weight, but contains no negative weight cycles.
From this I w...
Hi everyone! Was wondering if anyone wanted to help me out on my homework problem that was similar to the one I posted here yesterday. I posted a code specific problem on SO, but I'm getting a negative response to the question. Any help is appreciated as I'm really confused!
I'm working on an assignment to create a Self Ordering Binary Search Tree what re-organizes itself every time a duplicate element tries to be inserted into the tree. I'm having a few errors that I need help solving.
First, the root of the tree never changes (which i'm assuming the problem is in ...
[Note this is a question related to study in a CS course at a university, it is NOT homework and can be found here under Fall 2011 exam2: http://www.cs.ucf.edu/~dmarino/ucf/transparency/cot4210/exam/ ]
Here are the two questions I'm looking at from a past exam. They seem to be related, the firs...
Personally I don't think that "Please debug my code" is a good question. It's already annoying enough if you have to debug your own code. Nobody is going to feel motivated to debug somebody else's code unless it's very small and the error is easy to see. It's way too much effort (especially since understanding other people's code is already hard enough to begin with) for too little pay-off.
I think the idea is that it's too localized to your code. Any answer to your question won't help anyone else who might have troubles with the same algorithm because his mistake will be different.
I think SO is more meant for "How do I..." questions (which also qualify as everyday programming problems). I think it's a pretty common opinion among most regulars that a good question is one whose answers will be helpful to more people than just the OP.
Most of the site's design decisions (like for example not allowing users to delete their questions if it has upvoted answers) are built around that idea.
When I try give parts of the program that I think are the only relevant part of the problem, I only get comments that say, " I refuse to help unless you give the entirety of your code..." but, when I give all the code, people tell me that it's too much lol...
Turing-complete basically means that there's some way to use a string or a number (of arbitrary size) as input, and some way to produce a string or a number (of arbitrary size) as output
@Ell Turing completeness is only about what's computable, not about what kinds of user interaction (or other IO) you can perform. Turing machines have no concept of IO.
Yeah what is demorgan's law? no joke :P I will google it first though
"The negation of a conjunction is the disjunction of the negations. The negation of a disjunction is the conjunction of the negations." I still don't get it :P This stuff just goes over my head tbh
What is the right site on the Stack Exchange network for computer science questions?
None of the answers I can think of are remotely satisfying:
Stack Overflow: Even if CS questions are acceptable (some get closed, which I think shows they're not getting the right audience), where is the exper...
You have 1 coin. You may flip it as many times as you want.
You want to generate random number r such that $a \leq r \leq b$ where r,a,b $\in \mathbb{Z}^+$.
Distribution of the numbers should be uniform.
Its easy if $b -a = 2^n$.
r = a + binary2dec(flip n times write 0 for heads and 1 for...
should questions like BigO, Running Time, Invariants - Learning Resources be tagged with resource-request ?
This might apply also to many of the big-list questions.
Suppose I have two strings. Call them A and B. Neither string has any repeated characters.
How can I find the shortest sequence of insert, move, and delete operation that turns A into B, where:
insert(char, offset) inserts char at the given offset in the string
move(from_offset, to_offset) mov...
I believe I have a reasonable grasp of complexities like O(1), O(n) and O(n2).
In terms of a list, O(1) is a constant lookup, so it's just getting the head of the list.
O(n) is where I'd walk the entire list, and O(n2) is walking the list once for each element in the list.
Is there a similar in...
Can every linear grammar be converted to a form in which all productions look like $A \rightarrow ax$ where $a \in T$ and $x \in V \cup \{\lambda\}$?
A directed graph is said to be unipathic if for any two vertices $u$ and $v$ in
the graph $G$, there is at most one simple path from $u$ to $v$.
Suppose I am given a unipathic graph $G$ such that each edge has a positive or negative weight, but contains no negative weight cycles.
From this I w...
[Note this is a question related to study in a CS course at a university, it is NOT homework and can be found here under Fall 2011 exam2: http://www.cs.ucf.edu/~dmarino/ucf/transparency/cot4210/exam/ ]
Here are the two questions I'm looking at from a past exam. They seem to be related, the firs...
