Comments by Arthur V. Ratz (Top 200 by date)

As I've already explained below:

Also, for sets, below, my code returns:

"" "a" "ab" "abba" "ca" "" "bc", the return is "True"
"" "aa" "abb" aba" "cab" "ca" "" "bac" "" "dd", the return is "False"

And that's the only possible correct result for your assigment.

I'm sorry, but for your dataset from the pastebin it will always return false because the first line is always an empty string. Read your previous posts, carefully. Good Luck.

String s1 = "abcdefhi";
String s2 = "nnmmzztt";

Console.WriteLine(s1.IndexOf('d')); # strchr
Console.WriteLine(s1.Equals(s2)); # strcmp

No. Please for this matter run my code in C++, only, to reproduce an error. As I've already explained, this code is working correctly for me and your dataset. I still cannot figure about what the problem is. If you would like I can submit screenshots of my code returns the proper results.

So here's my final update to the solution :)

I've modified the code to read strings from the pastebin. You may try running the latest version of the code. For me, it works just fine for either case, such as "True" or "False", both.

So that try this out if you would like and paste your response, please.

In this file, a string at each line does not contain spaces or any other delimiters. Are you concatenating all of the strings into a single array/set? Let me give it a try doing this. And, I'll get back with my opinion later.

Could please tell me how you've parsed the strings from pastebin, after reading the file line-by-line?

Also, to implement this algorithm smartly, it's better to re-work my code and use the memory buffers re-allocation with std::malloc, std::realloc, as well as new/delete C++ operators, rather than store data as 2d-arrays, though.

The complexity of an algorithm without empty-strings of O(N)-is proportional and with empty-strings occurred it's O(N-e), where e is the number of empty strings. In the empty strings case, it must have been even faster than without them.

As far as I can understand, this problem does not have an impact on the general performance, nevertheless, empty strings are processed smartly or not. Why do you think that the empty strings issue and performance are related problems, here?

And yes, here's another solution above. To do that, for each string, check if it's a non-empty string (lines 31-35), and if so, compute the M's row for non-empty strings, maintaining another index n of non-empty strings in M's rows. Finally, if empty strings were found, the matrix M will have empty rows of 0's, at the final positions. Just don't care about that and build another matrix I, regularly, since the dot product of two zero-vectors is the scalar 0. It doesn't impact the result of composition, as such.

Lookup into my code above, and give a try, running it.

1. Just find the count of non-empty strings, first, and after that build matrices M and I of the specific shape, observing non-empty strings quantity.

2. Do the check after line 29, whether a current string is not empty. If it's a non-empty string, compute its row, normally, otherwise bypass it and proceed to the next one.

All right, just let me see...

No. Just do the complete empty strings removal, better, first, and then finally apply the algorithm.

When done, just let me know about it. All right?

Working??

Working??

Also you can add this f = strcmp("\0", string) == 0; to the line 15 of the code, above.

Just remove a string in the first line, or do a check. If the string scanned is not empty, if not do the computation for that, or proceed with the next line, otherwise.

You might want also to try this. See the code fragment, from above.

Here's a small update to the code, working for 1-string sets. Probably, this one is what you need. :)

Just a moment. I will post my Angular 7 solution later on. Just stay tunned...

To do that, print out the $_POST header by adding the following line of code at the top of your file echo json_encode($_POST);

Also, you can check with if 'e_subject' and 'verify' variable values are not empty and assigned to proper values.

Thanks.

I've tested your PHP-code submitted. Nothing seems to be wrong since it works as just fine for me and the errors you have mentioned didn't occur. :) The $e_subject string is constructed from a text literal and the value of $first_name variable. :)

Thanks.

I'm always ready to help an inquirer. However I can not help you with swift, because I never worked with it. And also I'm a bit short of time right at the current moment. But if you have any other questions, just don't hesitate to ask them.

No not at this time. Sorry.

Do you need my help any more ? If so, post your message here.

1. You need to install oracle virtual box;
2. Copy all folders from VirtualBox VMs folder to the similar folder under %USER_PROFILE%\VirtualBox VMs folder;

3. Run JavaSTServer and JavaMTServer VMs.

4. Run JavaClient#1 and JavaClient#2

5. Login as root on STServer, MTServer and JavaClient#1, JavaClient#2 using the following cridentials: login: "root" password "nullex"

FerdouZ, I've got a solution ready. Can you review the solution ?

FerdouZ, sory for my late reply. It was a file hosting problem. Now, I've updated the link to archive, so you can feel free to download and use it. It's interesting to me if the following code works for you. Just post your comment below after you've tested the code.

Ferdouz, I've posted my solution update as the solution 2 for your question. Download file using link below and tell me if it works for you or not.

No problem, sir. I will help you out. I'll post my improved code just a bit later on. I'm currently working on it.

Unlike java, C# Xamarin uses different API for adding notifications functionality.

You're very welcome, sir.

Just for your interest, this subject is worth to write an article about. I mean Java Sockets related questions.

This is just for my interest. :)

Please, finally, let me know if all these stuff I've posted as the solution, was helpful or not.

STserver, in this case, supports only one connection from MTServer

Here's your solution receiving user input, posted above.

Does it actually mean that the client app must receive a user input ? If so, I will post an update soon.

Sending multiple values from each client by timer ticks was already implemented. If you want to change this app's behavior with your own, please tell me what your client app is supposed to do, and I will try to help you out.

FerdouZ, now you can use the code for sending request messages without timer so you're able to send message/data manually from clients and it will reply automatically from server...

Yes you can. I've used timer for demonstration purposes only. Need a modified code ? I will rework client app's code and post it as the solution.

Hello FerdouZ. I've added specific comments to the code so you can understand it properly. Also, I've provided the explanation of basic idea for this solution. Please, read and leave your comment if you can understand the solution now.

FerdouZ, here's my solution below.

Does it actually mean that you want to render ad on start-up before the main app's activity layout is rendered ?? If so, here's my solution below.

And also, you would probably better tag your questions like "This is not homework..." when posting it to the forum.

okey. enjoy it.

I'm sorry, but I was ready to help not really knowing that this is "do my homework question". In advance, I will simply not answer the questions like this. I'm sorry. :) Thanks for your comment.

I'm sorry, but I was ready to help not really knowing that this is "do my homework question". In advance, I will simply not answer the questions like this. I'm sorry. :) Thanks for your comment.

I know that both of my solutions might come to be complex and difficult to understand but probably there's no other solution to this problem apparently. Specifically I use vector of structure objects to hold the data on each coefficient and each subscript, and then sort this vector by the values of subscript variables. Without it you'll probably never sort this equation.

Probably this one is better since your question is about C++ programming.

What's wrong this solution ? It really works.

I'm just a little bit busy right at this moment, that's why I've not written and added comments to my code. I'm sorry, I'm about to add some comments later on. Anyway, thanks for your comment. :)

Specifically, I use while loop to create an endless task with messages boxes pop-ups that is terminated when and only when a task cancelation token is requested. That's why before each driver addition phase I perform a check if the IsCancellationRequested property value is set to "true". If not, the task will continue its execution, otherwise it will terminate (or just "end-up") with particular token requested.

Unfortunately, the author of this question has not posted the code that specifically performs a driver addition. Probably, there would be more other recommendations regarding the task cancelation. *BUT* anyway, try to use what I've already advised with your own code and check if it works. On my side, it works well for sure.

You normally can interrupt this task the same way. Message boxes is for demonstration purposes only. Replace the code displaying message boxes I posted with a custom code adding a driver and you'll see that it works. :)

php + javascript + jquery is *NOT* ASP.NET. Unfortunately you normally cannot call javascript function declared in a html web page from inside a php or any other script.

You're welcome. If you've got any questions, just don't hesitate to give them in your posts under this subject.

Have you read article from my solution ?

Anyway, I'd kindly appreciate for any ideas how to make using PRNGs in C# better.

Thanks for guidance. I really have not done any stats tests yet at now. As for more sophisticated STL C++ PRNGs I know about them, but I would have liked to stress that at least simple std::rand() normally provides better results than those similar functions in C#.NET.

Now, I'm working on the code in both C++ and C# that implements an AI genetic algorithm. As you've probably might know, the initial population of chromosomes in this case is randomly generated by using PRNGs. Specifically, for the genetic algorithm initialization purposes it's strongly recommended to use normal random distribution created by using for example Box-Muller transformation or suppose MersenneTwister. When I normally use std::rand() function in C++ which is very simple, I obviously get the desired quality of random number generation.

Another case is libraries and packages for C#.NET such as built-in System.Random() or MathNet.Numnerics library. In spite of that those libraries for C# allow to either perform plain random numbers generation or sampling to get various distributions including normal distribution, all those libraries for C# really don't do what they're all supposed to.

To be more specific, I normally get very different results on the code that implements a genetic algorithm in the either C++ or C#, at the most part because of the random number generator used. When I run the code written in C++ based on using std::rand() function everything is going well, and not when running C# code unless otherwise.

Yes, thanks a lot. I've noticed this article was published a week ago, but I decided to read it later on and lost it. I know this is a good article and I will read it soon for sure.

Thanks for your reply.

Please, state your problem or assignment.

I agree with Rick Your, you normally should define a structure called LinkedList instead of class. That's easier.

I completely agree with CPallini

As I've already explained that there's no appropriates solution in which the knight stops in all four corners of the chess board.

What solution are you expecting to see ? For this problem, I've already posted a solution (see Solution 2).

I'm sorry but you've made a mistake D-4, E-2, G-1, H-2, G-5, H-6, F-8, G-6, H-7, F-7, H-5, G-8, E-7, C-8, A-7, B-5, A-3, B-1, C-3, A-2, C-1, B-3, A-1, C-2, E-1, G-2, H-3, F-3, H-1, F-1, D-2, E-4, G-3, H-0, F-2, D-1, B-2, A-4, B-6, A-8, C-7, E-8, G-7, H-4, F-4, E-6, D-8, B-7, D-6, F-5, E-3, D-5, F-6, G-4, E-5, C-4, A-5, C-6, B-8, D-7, C-5, D-3, B-4, A-6

The knight cannot move from G-1 to H-2. Just check with a chess board. :D

O'key. No problem. I'll take into account the latest problem's update.

As far as I can understand, according to your theory the knight cannot touch all squares by stopping for a rest at each of the four squares in the chess board. That's impossible.

It normally is able to make 8 moves. And so what ?

yes, that's right.

Nobody is in doubt that. In my solution the knight jumps straight, for instance: (F;1) -> (H;2) and so on.

I'm sorry, but this is only solution to this problem I have found. I've got no more ways to solve this problem but this.

yes, definitely, to "hover over".

The number of moves cannot be the challenge requirement. There was not a word about that.

According to the problem statement, there's no matter how many moves the knight makes, but it's supposed to touch all corners. In the other words, the number of moves cannot be a correctness criteria for this particular case.

I'm sorry, but Graeme_Grant has stated that 8 x 8 grid has a fixed number of moves - 8 x 8 - 1 = 63...

I'm sorry, but I also refer to Wikipedia's article too, but by reading this article I didn't find that it was mentioned directly. I refer to the animated chess board illustrating knight's moves. It still normally touches all corners by touches both sides of a corner. Look more carefully at this.

No that's wrong. Normally chess table 8x8 has about 26,534,728,821,064 directed closed tours. I refer to https://en.wikipedia.org/wiki/Knight's_tour

Oh, Probably you're not understanding it. If the knight is supposed to touch a square at the point where it comes to rest, you'll never build a path in which the knight's touching all squares this way.

I mean there's already multiple paths that include upper right corner of the chess board, hovering the knight over the either (F;1), (H;2) or (G;1), (H;3).

Multiple opinions ? That's good.

I've already got multiple touches, for example: (F;1),(H;2) and (G;1), (H;3).

For example: (A;1)(B;3)(D;2)(F;1)(H;2)(G;4)(H;6)(G;8)(E;7)(C;8)(A;7)(B;5)(A;3)(B;1) Moves = 14 - touches (F;1), (H;2),

whereas (A;1)(C;2)(E;1)(F;3)(G;1)(H;3)(G;5)(H;7)(F;8)(D;7)(B;8)(A;6)(B;4)(A;2)(C;1) Moves = 15 - touches (G;1),(H;3).

if it's not, what does it mean "to touch a square" unless otherwise ??

The variety of paths produced by the following code also includes the complete path given in question e.g.:

Example:

Start at: A1
Solution: A1 – B3 – C5 etc

Answer: Here's that:
(A;1)(B;3)(C;5)(D;3)(E;1)(F;3)(G;1)(H;3)(G;5)(H;7)(F;8)(D;7)(B;8)(A;6)(B;4)(A;2)(C;1) Moves = 17

And also, I believe that my solution is rather efficient since it allows to select the most appropriate path from the variety of all possible paths found by the code I've suggested.

ProgramFox, all these two paths:

0. (A;1)(C;2)(E;3)(F;1)(H;2)(G;4)(H;6)(G;8)(E;7)(C;8)(A;7)(B;5)(A;3)(B;1) Moves = 14
1. (A;1)(B;3)(D;2)(F;1)(H;2)(G;4)(H;6)(G;8)(E;7)(C;8)(A;7)(B;5)(A;3)(B;1) Moves = 14

*ARE* *VALID*. The first and second paths really touch all squares:

(F;1), (H;2) - 1st corner
(H;6), (G;8) - 2nd corner
(C;8), (A;7) - 3rd corner
(A;3), (B;1) - 4th corner

That's all. If you've got any more comments or questions, just post your message.

You can check it with http://www.calculator.net/standard-deviation-calculator.html?numberinputs=5.8589%2C7.1659%2C7.6630%2C8.6072%2C8.8960&x=44&y=13

I've fixed the code. I suppose this one will compute average and standard deviation correctly.

Fixed. Now it computes the standard deviation as well.

My margin of error is not very large, since you scarcely could find a circle with a smaller radius rather than the one shown in here: http://imgur.com/a/Oo0ah, having a radius 3.3.

And as you might noticed that all those circles in my resulting set having the same radius 3.3, which is definitely fixed.

About ellipses, we just don't discuss it.

Why do you think that multiple solutions cannot be ???
All solutions produced by my code are very close to one another and can be considered to be a single solution.

I'm sorry, you're right since "The circle may intersect points in the set."...

And also, see my plot diagram that illustrates the correct solution of this problem: http://imgur.com/a/Oo0ah

No, I think that the border is not allowed, because the points that reside on the border don't lie within the area enclosed by a circle. The belonging of such points to this area is in question.

I'm afraid that your solution has the number of disadvantages: the first one is that it allows to find just one circle, and another one is that any points from the dataset should *NOT* reside within the border of a circle, which you'll never achieve by using your algorithm. The "geometric mean" formula that your algorithm relies on doesn't allow to find the desired approximation and thus it's impossible to find an appropriate radius of a circle that encloses all points inside and *NOT* at its border.

I've recently made some improvement to my code, so it always allows to find a circle that surrounds all points in the dataset. The correct value of radius is *NOT* 3.18695, *BUT* r = 3.30, to enclose all points and that's the best approximation. I'm very sorry, but my vote is 3 on both of your solutions 5 and 7. Thanks for reading my comment.

Thanks, ppolymorphe for the clarification. I've re-mastered my code and now it's obvious that the smallest radius for this dataset is 2.2.

I'm sorry you actually should increase the precision by reducing the parameter precision_r by assigning it 0.01. This will actually give more results including circles with the actually smallest radius possible.

I'm just working to improve my code so it can produce a larger output dataset when the radius precision is increased to 0.01.

ppolymorphe, thanks for your comment. To obtain the circle with smallest radius, just reduce the radius precision_r to 0.01 and gradually after the code execution you'll get a circle with smaller radius surrounding those points. Thanks.

And also, let me tell you what exactly my code does: it's simply aiming to iteratively find those coordinates and those radius values by using which we can draw a circle (not ellipse) surrounding all points in the dataset. This is typically done by using circle equation to test if a certain point belongs to a certain circle region with specific coordinates and radius. If we apply those values of a point coordinates, a circle coordinates and radius to the circle equation which is (x - coord_x)^2 + (y - coord_y)^2 <= R^2 and the condition is true, then we simply consider that point (x;y) is surrounded by the circle with coordinates (coord_x; coord_y) with radius equal to 3.

Isn't it clear ??

Hi ppolymorphe, Who told you that "If you have at least 2 circles that surround all points, there is another circle with smaller radius that will surround all points too...". - from my position it's simply not correct, though. The smaller circle enclosing all points might or might *NOT* exist.

Here's a quick steps for testing the sets of circle's central points and radiuses from the output that should enclose all of the points in the dataset ( { { 0.5, 0.75 }, { 1.25, 0.85 }, { 3.86, 2.19 }, { 2.11, 4.65 }, { 1.17, 2.01 }, { 3.19, 1.63 } } ):

1) Take an arbitrary point from the dataset, for example (3.86; 2.19);
2) Take any of central points and radiuses provided in the output of my code, for example a circle at (2.29; 2.98) with radius 3;
3) Perform computation by using the following formula to determine if a point taken from the dataset at step 1 is enclosed within the specified circle with coordinates and radius taken at step 2:

(3.86 - 2.29)^2 + (2.19 - 2.98)^2 <= 3^2, which is 1.57^2 + (-0.79)^2 <= 3^2 <= 9, 2.4649 + 0.6241 <= 9, 3.089 <= 9.

And at now, don't you still understand my idea of how to solve this particular problem ??

But, what particular points from the dataset: { { 0.5, 0.75 }, { 1.25, 0.85 }, { 3.86, 2.19 }, { 2.11, 4.65 }, { 1.17, 2.01 }, { 3.19, 1.63 } }; you've actually taken for this test. In your comment, you provided only central points of a circle and radius. If you take any point from the dataset it should exactly work. The example of computation I've already posted as the reply to ppolymorphe's comment (see. above).

ppolymorphe, if you've got more questions, just post your comment, so I'm happy to answer your questions.

Hi, ppolymorphe. I'm sorry, *BUT* I'm not understanding your comment: what does it mean that you get center "around" (1.75, 2.5) with radius "around" 2.2 ??? My code normally ensures that you find all circles with center in (coord_x; coord_y) and specific radius_min value enclosing all those points in my dataset. Just to check if it's true you can take one or more points from the dataset, for example, (3.86; 2.19) point and coordinates of circle like (2.29; 2.98) with radius 3 taken from the output, and check if the following point is enclosed within a circle by using the following equation (x - coord_x)^2 + (y - coord_y)^2 <= radius^2. And obviously we get (3.86 - 2.29)^2 + (2.19 - 2.98)^2 <= 3^2, which is 1.57^2 + (-0.79)^2 <= 3^2 <= 9, 2.4649 + 0.6241 <= 9, 3.089 <= 9.

Probably, you cannot convert SFML to OpenCV Mat or so.

What does it mean: "two users request and response to each other". Normally in C++ we use WinSockets or COM to provide a communication between applications such as two user clients.

See my solution and it's obvious.

I've review your code and I have no idea exactly why this happens. Probably not all API calls can be hooked by using MS-Detours.

I hope that using try {} catch(...) exception handling mechanism will not help you in this case. Read my solution below.

I hope that there's no chance to open TDS files in VSS as well as PDB files in Embarcadero RAD Studio. That's actually a slightly different products.

O'key. Thanks.

Agree that, the following code is not the correct one since the multiple warnings telling that 'x' and 'y' might not be undefined. You can make sure that the following code's correct output is 13 (e.g. 6 + 7 = 6 + (6 + 1) by running this code here: http://codepad.org/n9uSsw2Z

1. "You are assuming that 13 is the correct answer...", if not, so I wondering what the correct answer actually is ?
2. "I also amazed by the phrase 'operator precedence violation'...What exactly the code violates?", normally this code doesn't violate anything, by this phrase I actually meant that there's multiple operator precedence violation such as x = ++x; y = --y; or z = x + ++x;, which normally causes on 'x' and 'y' might not be undefined serious warning as well as obtaining the incorrect results while performing the computation.
3. Finally, the correct code in this particular case is similar in both C and C++, since there's no way to use prefix increment in z = x + ++x;

That's it.

+5. Good comment. Very clear.

+5.

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I'm not sure, but it seems to me that you have to use Windows 10 SDK to be able to use EdgeHTML.

You're welcome

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O'key

Good solution. +5

Good solution. +5

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Good one. +5.

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Good solution. +5

Best answer using unions. +5.

Thanks. I'll keep that in mind.

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Good solution. +5

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First you should consider what these warnings are. If they don't affect the program execution just disable them the way I've shown in my quick solution here.

Good one. +5

As far as I'm concerned S19 is an executable for your hardware platform, or not ??

See documentation for Kinetis Design Studio IDE. Probably there's an option to convert embedded C into S19 file.

Good answer. +5

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And one more question: why do you actually need html for Microsoft Edge browser. Is there any difference between IE html and Edge html since they both are developed by Microsoft ??

Good answer. +5

He doesn't need to try step-into debugging. Really it seems to me that implementing this function is not actually needed, or if otherwise what actually the purpose of this function ??

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You're welcome. No problem.

What do you mean ?

O'key I've upvoted your answer 5 stars. Good answer.

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O'key. I agree with you. +5

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I also agree with you.

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If you need to compute the expression represented as string you'll need to use polish notation which makes the computation more efficient in this particular case.

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If you don't need loop while don't you use goto operator instead. But it's poor programming techniques.

Also you can use the file contents mapping into a buffer using mmap function.

you can measure the real execution time by using clock() function before and after the code execution.

+5. Good solution.

Have you tried using Intel Parallel Studio XE libraries for that purpose. I know that there's the number of libraries that allow to work with audio data.

It depends on how particular your device is working through its electronic circuit.

It seems to me that it's to find intersections between different geometric shapes ?!?!