Posts by Hiroshe

Yes, you'll need to download the source, apply the patch with diffutils (or manually) and then you'll need to recompile it and install it.

I have done the determination of the multiple and the multiplication tables already

Then what do you need help with? The print statement?

This happens if one move have reverse another. One way around this is:

Use a hashtable (or anything with near O(1) read/write) to keep track of all of the positions already visited. If a move results in a position being revisited, skip that move.

This has a second effect: if nothing is deleted from the hashtable (it's state is kept throughout the entire computation), then you'll also ignore entire branches that your already visited elseware, making it find the solution the faster.

You'll need to inisialise it with another method if you don't like getInput.

Also, I guess its one of the Must Know things to be a pentester

I wouldn't say it's a must know thing, depending on the kind of pentesting you're hired to do. It doesn't hurt though, and if anything it does give you a good way to learn how to organise your software.

so I guess i'll have to learn to use it

Look at the official documentation instead of some script kiddies video. Also, practice adding your own exploits to the framework (even if their old or non existant) to get a feel of the machanisms of the framework.

I am wondering would that also work for windows 7? or Linux? Why?

Metasploit is a framework that manages exploits (think of them almost like plugins). There is no restriction on the kind of exploits that may be included. Thus, the only restrictions on the target OS's is the capabilities of the exploit itself.

The one in the video will not work on any updated computer (for people who don't want to watch it, it's a java applet that the user needs to run based on some fixed exploits). However, if you intentianally made a Windows 7 VM vunerable to the attack, it would probably work.

public Product(final String product, double price)
{
    this.product = product; // assign product name
}

So this constructor takes in a string for the product, and a double for the price. Notice that the price is not saved.

Product product = new Product("200.00", 0);

The first argument here is the name of the product. 200.00 doesn't seem like the name of the product though. And 0 doesn't look like the correct price either.

Try to represent the "possible" solutions/states to this puzzle as a tree on a peice of paper. (Notice at each stage you have a finite amount of options, each option bringing you to another state).

Next, program a representation of state and start searchong for the solution using backtracking (this is implemented with either recursion or a stack).

Couldn't be much simpler then that.

Is LFS (Linux From Scratch) bulletproof?

No. If you want something more stable, use a full distribution.

The best way to choose structures is to look at how often you'll need to use each operation and the time and space requirements, and base your choice on that. For example, you might choose an AVL over a hash table if you're working with real time applications because the worst case for hash table insertion (given that we don't know the maximum size) can be disastorus. You might choose a skip list instead of an AVL because of the concurrent access properties of a skip list.

But generally, balenced trees are often more usefull in situations where that data needs to be sorted, or more flexible serches must be performed.

For example, if you want to find a range of numbers in a set you might want to use an avl tree. This extends to other kinds of search criteria.

In "popular" practice, more complicated vartiations of balanced tree's are often used for databases (thus AVL is a good place to start if you want to learn the actual strucutres used). Also, AVL's specifically are used by one of Linux's schedulers I beleive.

I don't generally EXPLICITLY use them. However, they may be used by some mechanism I'm using. Sometimes it comes up as a thought experiment though (ie, when compairing various data structures I could be using). I sometimes consider using them if I'm actually implementing something computationally interesting though (which doesn't come up often in practice). For example, real-time operating systems.

Your solution looks too complicated for the task. I'm not going to bother trying to unravel it. Also, it looks like you didn't break down the problem well enough. Spend time and think about how you solve it before writting down code.

Also use comments. It looks like you got confused by your own logic, and ended up writting some unusual things.

I'm going to try to break this down for you.

1) You are given a k. You must validate k to make sure it's an integer more then 1 and less then 22. k shound NEVER be modified beyond this point. Think about it: If k changes, then your changing the question. (I can see when you wrote k++ in your old code, and at that point you didn't know what your program was doing).

2) The outerloop has one job. Iterate i starting from 2 and ending when the test passes. It's that simple. You don't need to validate k on. Every. Single. Iteration. Keep it simple, because this loop IS simple. If you want, you can exit the loop using a 'done condition' and that's it (there are more advanced ways to exiting out of nested loops, but I don't think it's worth learning them at this point).

3) The innerloop has one job. Iterate j starting from 2 and ending with k. Inside of this loop, i is tested against j. If it fails, then continue the outerloop. If it passes, then continue the innerloop. …

Game::sortbyScore

Wait, in your first post it was just sortbyScore. Try the suggestion in the error message, and reference it with &Game::sortbyScore as the third argument.

It looks like your on the right track. I'm not going to bother putting it into my compiler to verify though. Is it working for you? Did you run into problems when you comment out line 26?

I think it might be that software engineers learn more about software implementations, and computer scientists learn more about the theory of computation. Though, there is crossover.

For example, as a software engineer you might expect to be asked to implement WebGL in a web browser. As a computer scientist, you might be asked to make a schedular for the "job shop problem" in a maufacturer. Though, the crossover is very high dispite the fields themselves being different, and more often then not you're competing for the same jobs (though sometimes csers go into the direction of research and algorithm development).

It's been asked before. My vote goes to vim.You don't need much mroe then a text editor your comfortable with for python.

Another idea might be a personalised score, where if you like that review, then (instead of giving reputation to a user) your personal score that you see weighs that persons reviews higher in the scoring proccess. Also, it slightly weighs people who agree with that person and their opinions slightly higher. That way users are "bubbled into" a mroe agreeable score according to their preference.

The problem (benifit?) with that is it will require some user interaction to determine what they like to see. Of course this creates a bit of a bubble (by design), but sometimes it can be usefull to determine if you'll like the content or not.

You can use a PageRank like algorithm to do this quickly and accurately.

There is no incentive here for unreal rating. In fact there is an incentive to rate well. Consider how the average rating comes out. Say the first user rated it to be 9/10 he doesn't know if in future other's will rate it same as him or not, so, his best bet is to rate it real and thus expect others who rate real to give it the same rating. Then comes the second user, the same problem rises for him too so he also has to rate real and so on.

Ok, let's say that the average is 8/10. However you didn't like the web site. If you rate it lower, then you'll get less reputation even if your review is great. The existance of that insentive breaks the statistics (any statition would agree that for accurate statistics, there can be no insentive). From a statistics standpoint, this is flawed (this is one things thats stressed in first year statistics).

Also, if you do this, you need to consider other statistics like standard deviation, and even grouping sometimes. If a web site has high standard deviation, then it would be inaccurate to give more reputation to people who rate close to the average, since it's not representitive. For example, in an extreme case, consider a web site that has 50% 0/10 ratings and 50% 10/10 ratings. The average is 5/10, but it's not representitive and nobody gets the extra reputation. (in mathematics, extreme cases are a good …

WOT has fuller reviews, but it is focused on saftey. Alexia is an example of how statistics can be used.

First of all, a user gains/looses reputation points on getting up/down votes on a review he/she writes.

That's standard. We have a simular system at Daniweb.

Secondly - the idea - I aimed at kind of simulating up votes on ratings itself - i.e people agreeing with your rating.

Well when a user likes a review, they don't nessecarily like website. They like the review. If the review is good and rate the movie as bad, then if anything a an upvote should be a downvote for the movie. Also, sometimes reviewers will like over reviewers posts which creates a bias towards the reviewers who get 2 votes. So be carefull.

Say a user gives 5/10 rating to a website then if any other user in the future also gives the same rating to the website then you gain reps

This is what I just cited not to do. It gives users an insentive to make reviews that agree with the average (so then the users gets more reps) which is a bias towards the norm. You need to make sure that their is NO incentive to write a review with a specific rating in order to avoid biases. Users should be given reputation points to write a good and well thought review, reguardless of what the actual score was.

The system your talking …

Because I think this is a very simple idea but that has not been implemented yet.

Plugin and reviews: https://www.mywot.com/

Rankings and other statistics: http://www.alexa.com/

A user with high credibility points, rating the web site is more valuable than a lower credibility user.

This isn't anything new, and I would expect it of any ranking service. It's just using statistics to get meaningfull summaries of the information. If you can make an interesting ranking algorithm (that does not introduce bias!), then you might be able to make a project based around the algorithm itself.

It's easy to introduce bias though. For example, if you make an algortihm that give users who score closer to the average more reputation (makes intuitive sense), then users will choose scores closer to the average for more reputation, introducing a bias.

If you make an interesting algorithm (and the project will be based on the algortihm, so advertise it as an "effective rating algortihm implementation"), then it would be something interesting.

Computer Science isn't about programming. Sure, naturally Computer Science takes a problem and breaks it down into something so simple that a computer can do it; thus computer scientists also learn how to program usually. A computer scientist can take a computational problem and find an effective way to solve it (and probably implements a solution).

In any case, let's look at an analagy. Say you learned English. Does that mean you can write a good novel? No, it doesn't! It doesn't matter how fluent you are in the language; it means you can read and write English. It has nothing to do with how well you can write a story. It's the same with programming. Just learning languages doesn't help you write good programs. Thus, programmers need to learn a little computer science to get the job done.

If you want to learn reverse-engineering, bug alanysis and pen testing, that's more to do with software engineering and applied computer security then computer science (this doesn't have much to do with computation). A software engineer specialises in the development of software and is more applied.

That being said, there is no reason why a computer scientist wouldn't be capable of reverse-engineering, etc. It's not the focus of the feild, but a lot of computer scientists are also great software engineers (in the same way that a software engineer could be a great computer scientist).

EDIT: I should also point out that a lot of people and even schools incorrectly call …

A website which allows users to add websites/web-pages on the website for review. Other registered users in the community will rate the pages on a scale of 1-10 and may even write a review. Then for later, I can also create a firefox add-on which shows a wesite's rating in google search results.

I don't really know what your standards are, but essentially that's just a forum/review site. It's not interesting computationally at all. I would expect a high school web developer to be able to do that easily. Is your prof ok with that?

So, I'm in my final year of my B.Tech. in computer science programme

You're in your final year, but you haven't found something you might be interested in?

The problem with the 3 things you listed is that they don't have much do to with computer science at all. It sounds more like it's for "software engineering"/"software development"/"programming" which is a quite a bit different then computer science. Is that ok with you?

Also, they seem to be "big" projects, but they're not interesting (in a sense of computation).

For project's more clostly related to Computer Science:

1. How about a GPU-implemented neural network for phones. The problem with phones is that most don't have OpenCL/Cuda availibility, which means you'll probably want to use OpenGl shaders. I beleive this would be the first of it's kind, since most libraries I see are based on either Cuda, OpenCL or the CPU. It's also somewhat usefell, and can be interesting for a game.

2. It's not anything new, but how about you make a real-time operating system that focuses on energy efficeny? It's a little more interesting then a plain old OS. Yes, it should be very possible for 2 people to write it in 7 months.

3. Using MapReduce for a search engine seems like a bad idea (without some serious optimizations). If you wanted to (I'm presuming your good at linear algebra), you might be able to apply MapReduce to something like google's PageRank algorithm. I guess …

Well, I had 4 math classes in grade 12. Honestly, that made the homework very consistent, and made things fly by easily.

Also had a "serious" gf who broke my heart. Worked out for the best. You don't want a gf "from home" when you go away.

Very true. I avoided the idea of having a gf when I relised I was leaving town. Though someting simular ended up happening in university anyways.

You'll need more then javascript. HTML and CSS will give you most of the website, and if you need something interactive in the users browser, then you can use javascript.

HTML5, CSS and Javascript can do most things that flash can. Entire websites based on flash is more of a thing in the past now adays.

Not all mobile devices support flash (most don't).

And it's 100% because you haven't given us reason to think anything else, yet.

I think that the problem is that it looks like 700% using standard a 7-bit number display.

Well looking through your textbook is probably a good start for C. This site have a pretty good reference if you need to look up anything specific. Your assignments are probably one of the most critial parts of being a good programmer (experience counts).

help me please

Ok. I take it you want help learning more. Do you know what you want to learn (or be able to do) yet? How are you learning right now?

By the way, posting your code on Daniweb breaks this part of your licence:

You shall not disclose such Confidential Information and shall use it only in accordance with the terms of the license agreement you entered into with Nikolas9896.

as part of Daniweb's TOS:

Posts contributed to the community immediately become the property of DaniWeb upon submission.

Anywho, try compiling the "program1" unit and "main" unit seperately. Which unit cannot find the file?

If we had the error message like Moschops said we would know this, but sometimes it's better practice to break down the compilation so you can see which stage the error happens at and you don't need to recompile the project from the beginning. This can be automated with something like a makefile.

What would happen if we cut a flower and it would scream like hell of the pain it feels?

I'd probably invesigate the mechinism it uses to make the noise.

What would happen if we catch a fish on a line and it would squeal like a pig?

I'd probably find another method of harvesting fish.

Just wrap the example code I gave you in a loop, iterating through possible IP addresses. 200 LoC isn't very long at all, and I wouldn't think I can do much better anyways.

We're not going to write code for you. He help you learn how to program, and help you with specific problems you might have or point you into the right direction.

That way seems pretty simple to me. "ping all addresses and check which ones respond". In fact, I beleive the is the only practical way.

Another way might be to set it up as a packet sniffer, and see which hosts are actively sending and recieving traffic.

Unless you're talking about the implementation of ping. The answer is "not with pure python". There might be a module availible with an implementation of ping.

Don't ask the question in the title. Also, provide more information.

Your question is equvalent to asking "Why does this equation use 5: 5x^2 + 2x + 3 = 7?".

I'm assuming that this is for a cashe implementation? The reason why it has 4 select inputs is because it wouldn't work otherwise. If you used 3, then you're obviously missing a place where a hit could be found. Though I probably wouldn't impement it as described.

You can implement ping in python. Example.

Ask your user for an ip range, ping all of the addresses and see which one's respond.

C++ itself doesn't have many capabilities without help. You add capabilities by using libraries which are not "a part of C++ on default". You cannot make a GUI in C++ without using a library.

Windows API, FLTK, WxWidgets are all useable with normal C++. Googling any of the terms will bring you to their website.

I personally like FLTK since it's lightweight, simple, and it looks the same on all platforms (which is both a good thing and a bad thing).

Most library you with with will have good official documentiation. For example, here is the official documentation for FLTK.

Sounds like homework.

If you know how to use functions, then you should already be able to answer this question. If you don't know how to use functions, then look at whatever resource you're using to learn. If you don't have a resource to learn from, then we'll point you to one.

Sounds like you just want to do some widget based graphics.

Just use some GUI libraries for C/C++. Windows has a native API you can probably use from your compiler. You can also use FLTK (this draws things itself) or WxWidgets (this uses your platforms widgets) for something more cross platform. Qt is an excellent cross-platform framework that extends C++ itself and provides libraries for a lot of things.

Another approach would be to use a higher lever language for the GUI portion (and keep the core in C++ if you wish). I kind of like using Python for that.

C++ so learning new complex tuff is good

I donno about that. I mean, there are "advanced features of the language" and then there are "advanced programming concepts". I would say that alternating between learning the two is a good strategy.

And still I wonder if I can get it a little more complex

Well, if the story arcs are pretty much the form of a tree-like thing, you can make it more "complex" by addming more content - but that's not really increasing the difficulty because after a while it just becomes systematic.

If you want to make it more interesting, try to deviate a little bit from the if-statement style story (or in a sequal).

Make it so that it has some state to it (inventory, levels, hidden values effecting the story), and make it progress such that the player has some nagicational capabilities (as in there is some kind of grid of places the player can be - like a 2D array, and the story only progresses if the player is at the right zone and does the right "action"). And instead of simply asking the player questions, you can make it so that at each zone the player can perform various actions (like "check ground", "check tree", "use item", etc...)

You don't need to follow any of the ideas above (or you can do a subset of them), but they should at least give you an idea of how more "dynamically acting" …

Can't run it on Linux; but if the games like zork then it's probably a good project.

which im not certain if it qualifies as simple or complex

In all honesty, what does it matter if it's simple or complex? A good "thing" is a good "thing". Some good "things" are simple. Some good "things" are complex. Some bad "things" are complex. If you're interested in it, then you're good to go.

I'm guessing that the storyling is a series of if statement type questions (like how a visual novel might be programmed), branching into a tree-like fasion (it's a shot in the dark). You might be able to get something a little more interesting by keeping track of a few "hidden" values based on the players decision and have that effect some events in the story (for example, a player who never chooses the "brave" options might be required to be brave for the final stage). You can also implement a simple inventory and things like that. If you ever get towards a sequal, perhaps make it a little more interesting with an actual "grid" or structure of zones, and making the story progress as "events" that happen at the zones (giving the player a little more freedom to do "side-quests", gather supplies, explore other zones, etc).

The light and the resulting shadow is the 4th dimential element

Both the light and the shadow (the lack of reflected light) geometrically exist within 3 dimentions.

Nothing about dust (geometrically) is 4 dimentional.

3D Objects are allowed to hit other 3D objects without ever requiring a 4th dimention.

He carried on to do his PhD, studying the concept of a 4th dimension, of which he was awarded a fellowship and remains in charge of a research team there.

Nice. Does he have any papers published?

As almostbob stated earlier one of the easist to comprend examples of the 4th dimension is time when looked at past and present opposed to just the present.

Correct. 3+n dimentions can make sense when the other n dimentions are not geometric. Inclusing time, colour, static charge, magnetic feild strength, current, density, practically any observable property. The problem becomes fairly easy and clear to grasp in those situations.

The idea of light as a 4th dimesion element I mention earlier and how it casts a shadow on a 3 dimensional object also is an example that is easy to grasp.

I don't understand this point. We can and do project shadows using 3 dimentions. I can fire dust from a "dust cannon" at someone for example, and see an imprint of them on the wall behind them. Each of the particles has a very simple trajectory (not including graviety or air resistance). It's easy to tell which particles hit the wall, and which don't by checking for intercepting with the trajectory and the object. This boundry can be calculated continuously as well. The process is well defined, and a 4th dimention doesn't appear anywhere in the process (and even if the calculation did involve a 4th dimention, does it actually involve a physical interpretation of a 4 dimentional object in geometrical space itself?).

The 4th dimension does come into play especially in elleptic.

Don't get me wrong, I'm not saying that dimentions above 3 …

An easier way to understand this:

We can visualise an r->r function onto a 2D plot because what we know what "our" 2D is (it's a surface in our world). We can visualise an r2->r function onto a 3D plot, becasue we know what "our" 3D is (it's just like an object in our own world). We cannot visualise an r3->r function onto a 4D plot, because we have no idea what 4D is (we have no "our" 4D in terms of geometry of this world). For example, the idea of Perpendicularity needs to be generalised to Orthogonality before we can use it in higher dimentions (because perpendicularity is based on our world). This is generally defined by an inner product which can be chosen to the feild we're working with. Furthermore, even if we did make a generalized 4D world that in theory could be visualised by some being; our brains simply don't have the capabilities of creating a visualization of it.

That's not to say we can't work with functions in r3->r; it's just that we don't have a physical interpretation for it (and attempts to do so, which some people try to do, are senseless). We can of course do things like project it into 3D or 2D. That's just a bit of simple linear algebra.

We can also of course specify the "dimentions" of r3->r to be different things (like for example 3 geometric coordinates and the function returns the tempurature. Or for r4->r it can …

Hyperbolic Geometry (an instance of non-Euclidean geometry) can be generalized to n dimentions if you wish (just like Euclidean geometry). The only difference between Euclidean Geometry and non-Euclidean geometry is the fifth-axiom. However, you still face the exact same problem: there is no interpretation of a 4-dimentional object. Hyperbolic Geometry make no attempt as far as I know to come up with some interpretation. In fact, I don't see why it would make an attempt to do so - Hyperbolic geometry isn't based around multiple dimentions (though as I said, just like Euclidean geometry it can be generalized), it's based around changing the 5th axiom.

It's kind of like changing the colour of a pen, and expecting it to change the answer.

Your Calculus professor claims himself to be a geometer? As in an expert in geometry?

I guess so. I think it also means that he tries to think of the problem geometrically, and works off of that to work out a solution. I've seen him remember theorums by using geometric hints for example.

Do you recall a Kodak commercial from years ago with Mariette Hartley and James Garner. He says to her, "that doesn't make sense." She replies, "you mean you don't understand it."

If you can find somewhere that makes sense of the existance of a physical 4-dimentional object, I'll certianly be glad take a look! But I'm not basing my comment on "I don't understand it, therefor it doesn't make sense for anyone." Rather, I'm basing it on my own exploration into the feild (mostly from the geometric applications of linear algebra) as well as comments from an undenaibly good professor.

We've (the class) talked about this with my Calculus professor who proclaims himself a geometer, and he's mentioned that it's simply not possible to make sense of a physical 4-dimentional object; it doesn't have a physical interpretation. Obviously it can be projected just like any other vector space; thus we can "see" projections of it in 2D or 3D.

It's not a matter of not understanding it. It kind of remind's me of this video. It's not that the expert doesn't understand geometry and thus cannot draw 7 perpendicular lines - it's that he does understand geometry and it's impossible to draw 7 perpendicular lines.

I've identified the problem

clueless and helpless in C programming

If you have no idea how to program in C, then the only way I can possibly see you getting this assignment done is to learn C. I don't see how you are going to get it done otherwise. If you know how to program in C, try the question yourself first. If you're stuck, we'll help. If you have a specific question, we'll help.

We wont do it for you; because that doesn't really help anyone, does it?

Using time to represent the 4th dimension doesn't gain us really anything because we cannot change time.

We can still use it as an index. For example, we can talk about events that happened in 1964 because we are using time as an index to specify 1964.

Another example would be a movie. Or a computer simulation. In these cases, we're not talking about using the universes time, but we are still using the measurement of time to index through something.

Light can be a good example of the 4th dimension as it can be added or taken away. The affect of light we see everyday, young children understand the 4th dimension wrt light in reality. A persons shadow is created by the 4th dimension element of light. As the light moves so does our shadow. If the light is removed completely, exactly noon, or pitch black, we also have no shadow.

That's very vague, where as dimentions is a mathematically concrete idea. How are you using light as an index for anything? It's not impossible if you set up a(n) equation(s) representing a feild, where luminesce is a variable (thus giving you a set of feilds indexable by light); but that doesn't corrilate to your real world situation. A person's shadow is created by very normal 3 dimentional geometry.

The simplified explanation is the fact that you now have internal and external faces has created a 4 dimensional figure. It is easy to see …

It occured to me that since time is not constant but rather relative to the observer, could it really be a part of dimensional thinking?

If you wanted to, you could use time as some index if it's releavent to the problem at hand. There no reason why you couldn't use it (it is used as an index in practice a lot), and there's no reason why you should if it's not relevant to the problem at hand (again, often in practice we look at instances of time, or if we're dealing with things with arbitrary numbers of dimentions unapplied to the universe).

We've observed that the faster an object goes, the faster it precieves time. What interesting here is that there are a lot of different ways we can correctly state this as long as it's mathematically equvalent. So, another equvalent we can say us that: "the faster something goes, the slower the interactions between it's elementary particals happen (since all interractions can be modeled on that level)." So it's a little more like it's slowing down rather then traveling through time (though you are preceiving time as going faster as the observer; in the same sense that you'd "jump" through time if you were frozen in ice and somehow revived.)

A 4th dimention is not neccasarily related to anything in particular (including time). It's simply another index for whatever your dealing with. Trying to extend geometry to 4 dimentions is what doesn't make sense (though, it is possible when we make generalizations). It's not complex at all. Arbitrary and infinit numbers of dimentions are natural in linear algebra and calculus.

As mentioned, you first need to be using an operating system who's kernal calls are guerenteed to work in real time.

Then there are a few problems with the JVM itself (garbage collection, JIT, threading) that don't guerentee real-timeness. You'll need to find a real-time replacement JVM, for example JamaicaVM-PE.

Then you also need to be very carefull about how you write your program in order to assure that it runs in real-time.

Modern web browsers will employ encryption, though it isn't really helpfull withiout a master password.

See your web browsers specific documentation for details.

Yes, I was thinking of doing #include "file.cpp", but how would I link those two files together in order to access the other's functions?

You should NEVER need to include a .cpp file. Incliding the corresponding .h file has the same effect and is more powerfull, not to mention it will lead to faster compile times.

My suggesting would be to give up on includig a ".cpp" file, and try to do it properly.

I understand if only one or two functions are used that it is impractical, but what happens if you need almost all of the functions in the other file?

Even if you need to access all of the functions, what if you need to access all of the functions elseware? Now you're compiling the same code multiple times! Also, you'll need to include header guard macros in your source file, otherwise you might run into multiple definition errors. The source file might quite a bit larger then it would be if you just linked against a compilation unit.

Do many professionals use xCode for C++?

A lot of projects that are developed for mac do. If the project is supposed to be cross platform, I would expect to see some kind of build system instead of using xCode's build in one. Some project exclusively for Mac also stick to other build systems, so the choice is up to you.