Re: Visual C++ - C / C++ / MFC Discussion Boards

Re: lookup plan for hashtable

Richard MacCutchan20-Dec-10 1:04

Richard MacCutchan

20-Dec-10 1:04

Rather than asking someone to give you answers to pass your interview, you would do better to buy a book on C++ and learn it before attempting such an interview.

Just say 'NO' to evaluated arguments for diadic functions! Ash

Re: lookup plan for hashtable

Alan Balkany20-Dec-10 5:16

Alan Balkany

20-Dec-10 5:16

Some brief answers...

1. Hash tables can look up items very quickly, at the cost of more space and a fixed size. This is their main advantage. A linked list is good for unknown amounts of data; it grows as you add more data. Lookup requires going though (on the average) half the list, so is generally slow.

2. A red-black tree uses one extra bit of storage per node to avoid the worst-case binary trees (skewed). (A scapegoat tree accomplishes this without the 1-bit overhead per node.)

3. A class.

4. All mutual-exclusion mechanisms ultimately depend on an atomic test-and-set operation, which determines if another thread is accessing a critical resource, and sets a flag at the same time if the resource is free. This must be done by hardware; if this capability isn't available, no pure-software solution will be able to provide mutual exclusion.

Re: lookup plan for hashtable

NarVish21-Dec-10 2:44

NarVish

21-Dec-10 2:44

Thanks alot Alan. Is a class of type datastructure?

Re: lookup plan for hashtable

David Crow21-Dec-10 2:54

David Crow

21-Dec-10 2:54

HaroldVish wrote:
Is a class of type datastructure?

It's more of a fancy struct. See here.

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Visual C++

John50219-Dec-10 22:22

John502

19-Dec-10 22:22

At What Conditions,
CStudioFile::ReadString() Gives/Returns the FALSE value?

I know that,What is available in the MSDN ,
AnyBody Know the another Conditions Please,
Tell me.

And
In a File Consists the Lines In one Condition "m_pString" doesn't take the line in the File?

Why it Happen? Any body know Please give me Reply....

Re: Visual C++

Maximilien20-Dec-10 0:38

Maximilien

20-Dec-10 0:38

What make you think there are other condition than what is describe in the documentation ? Do you have a test case that will trigger a FALSE ?

It returns FALSE (or NULL depending on which version you call) if no data is read before the end-of-file.

John502 wrote:
In a File Consists the Lines In one Condition "m_pString" doesn't take the line in the File?

What does that mean : Confused | :confused:

Watched code never compiles.

Re: Visual C++

John50220-Dec-10 1:51

John502

20-Dec-10 1:51

Hello Maxi,
Thanks for helping in this regards; I want to run my test case on the below text;

12/13/10 10:11:00 (India Standard Time), [3484] TAPIAdapter.cpp :379 INFO - Closing the database before stopping the service.
12/13/10 10:11:00 (India Standard Time), [3484] TAPIAdapter.cpp :409 INFO - TAPIAdapterDynConfig thread could not be stopped
12/13/10 10:11:00 (India Standard Time), [3484] TAPIAdapter.cpp :429 INFO - "TAPIAdapter Service" Service Stopped
12/13/10 10:11:04 (India Standard Time), [3544] TSPConnector.cpp :166 TRACE - Line is closed for device_id 110
12/13/10 10:11:04 (India Standard Time), [3544] TSPConnector.cpp :166 TRACE - Line is closed for device_id 110
3_VOIP_10202010_00004 made on Oct 20 2010 16:41:29
12/13/10 10:11:00 (India Standard Time), [1508] TAPIAdapter.cpp :793 ERROR - Illegal keyword "CheckExtInCTIUserInterval" in configuration file
12/13/10 10:11:04 (India Standard Time), [1508] CVoipDatabase.cpp :167 INFO - KnoahSoftDB : Connection opened with database at ip address : 157.0.60.155
12/13/10 10:11:04 (India Standard Time), [4108] CCTIOSAdapterKSDB.c :142 TRACE - The SQL Query is :- select v.voip_phone_extension Voip_Phone_Extension,e.emp_code Emp_Code,e.emp_id Emp_ID,e.network_id Network_ID,s.site_alias Site_Alias From Employee E, Site S, Voice_Configuration V, Employee_Detail D Where V.Emp_Id = E.Emp_Id And V.Emp_Id = D.Emp_Id And D.Location_ID = S.Site_ID And V.Status = 'A' And V.Do_Voice_Recording = 'Y' And V.Voip_phone_extension != '-1' and v.emp_id not in (select e.emp_id from employee e where e.emp_first_name like 'extn_agent_%') order by voip_phone_extension

I have this text content in one file and wants to read this by application;

please help me out..

Thanks
John;

Re: Visual C++

Maximilien20-Dec-10 3:15

Maximilien

20-Dec-10 3:15

So what is the issue ?

You open the file, read the file line by line with CStdIO::ReadString and do what ever you want with each string :

something like :

CStdioFile myFile(_T("C:\\path\\to\\your\\file.txt"), CFile::modeRead |CFile::typeText  );

CString myString;
while (myFile.ReadString( myString ) )
{
    // do something with my string.
    std::wcout << myString.GetBuffer() << std::endl;

}

Watched code never compiles.

Re: Visual C++

Michael Schubert20-Dec-10 3:26

Michael Schubert

20-Dec-10 3:26

Pretty much the same reply he got from me a few days ago. D'Oh! | :doh:

http://www.codeproject.com/Messages/3701943/Visual-Cplusplus.aspx[^]

Go and never darken my towels again - Groucho Marx

Re: Visual C++

Maximilien20-Dec-10 3:33

Maximilien

20-Dec-10 3:33

Watched code never compiles.

how to compare two audio files

rajniyadav1a19-Dec-10 22:11

rajniyadav1a

19-Dec-10 22:11

Re: how to compare two audio files

Maximilien20-Dec-10 0:41

Maximilien

20-Dec-10 0:41

Compare what ? the file or the audio ?

With a lot of difficulties.

Good luck.

Watched code never compiles.

Re: how to compare two audio files

rajniyadav1a20-Dec-10 1:16

rajniyadav1a

20-Dec-10 1:16

i want to compare audio.

Re: how to compare two audio files

Maximilien20-Dec-10 1:34

Maximilien

20-Dec-10 1:34

With a lot of work and with the help of a Fast Fourier Transformation. (google for that)

And then there is the issue of file formats and sampling rates and all that junk.

Good luck.

Watched code never compiles.

Re: how to compare two audio files

Cedric Moonen20-Dec-10 20:49

Cedric Moonen

20-Dec-10 20:49

What do you mean by "compare" exactly ? Your question is totally vague, please clarify. And please describe your question in the body of the message, not in the header.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

Re: how to compare two audio files

rajniyadav1a20-Dec-10 22:07

rajniyadav1a

20-Dec-10 22:07

I have a large audio file (MP3 and wma). Now I want to find some particular Track (speech) in that audio large files. So How can I compare two Audio files Samples .

Device Context

002comp19-Dec-10 18:42

002comp

19-Dec-10 18:42

hello Friends

In my application there are too many windows and I want to know the device context(Handle) on which i want to draw mine image.How do I get that device context?
Any Ideas?

Regards
Yogesh

Re: Device Context

Richard MacCutchan19-Dec-10 21:23

Richard MacCutchan

19-Dec-10 21:23

See here[^].

Just say 'NO' to evaluated arguments for diadic functions! Ash

Re: Device Context

002comp19-Dec-10 21:48

002comp

19-Dec-10 21:48

THanks For Reply.
I am not able to use GetDc bcoz my application is multiDoc And am not having handle to the Window as there are too many.And GetDC parameter is Handle to that Window.

I tried FindWindow also to retrieve the handle of Display window but FindWindow returning null.
I am Using VC6.0

Any other Ideas.
Regards
Yogesh

Re: Device Context

Richard MacCutchan19-Dec-10 22:45

Richard MacCutchan

19-Dec-10 22:45

yogeshs wrote:
am not able to use GetDc bcoz my application is multiDoc

Then there is something wrong with your application, multi-document has nothing to do with Windows on the display.

yogeshs wrote:
And am not having handle to the Window as there are too many

Sounds like you need to reconsider the design of your application.

yogeshs wrote:
tried FindWindow also to retrieve the handle of Display window but FindWindow returning null.

Then you need to use your debugger to find out why it returns NULL. Check the status returned from GetLastError().

Just say 'NO' to evaluated arguments for diadic functions! Ash

Re: Device Context

bleedingfingers20-Dec-10 0:05

bleedingfingers

20-Dec-10 0:05

All you have to do is call GetDC() as Richard told you. And when you are done, call ReleaseDC(). It really doesn't matter if yours is a multi doc app as every doc (usually) has a window associated with it and GetDC() is related to a window.

...byte till it megahertz...

my donation to web rubbish

Re: Device Context

002comp20-Dec-10 0:49

002comp

20-Dec-10 0:49

Hello Sir,Thanks For Reply.I am using GetDC() but I dont have handle of my display window.And If i use NULL In GetDC() Parameter (HDC dc = GetDC(NULL)) then It is returning the Device context for Full Screen. but I need for only my dispaly where i have to draw mine images.

Any Idea for getting Handle of that Display Window Or anyother way to get DC?

Regards
Yogesh

Re: Device Context

Richard MacCutchan20-Dec-10 1:02

Richard MacCutchan

20-Dec-10 1:02

Look at the link I gave you, GetDC(HWND hWnd) returns the device context for the window with the specified handle. If hWnd is NULL then you get the DC for the entire display. That is the way it works and you have to code to those rules. If you don't have the handle of one of your windows then there is something seriously wrong with your application.

Perhpas you are not explaining your problem clearly. In most cases you would write or draw on the DC within your window's WM_PAINT message handler where all the relevant details are provided by the framework.

Just say 'NO' to evaluated arguments for diadic functions! Ash

Re: Device Context

bleedingfingers20-Dec-10 1:05

bleedingfingers

20-Dec-10 1:05

The only idea is to use GetDC() on a window.

I have some question. What are you trying to achieve? Is the window from your app or are you attempting to draw on some other app? To let people help you better, you have to respond to these questions.

...byte till it megahertz...

my donation to web rubbish

Re: Device Context

002comp20-Dec-10 1:13

002comp

20-Dec-10 1:13

Thanks For Ur Valuable Reply.I appreciate ur time for My Questions.
Let me tell you Again:
There Is an application which is used to draw some images or like that.
But Now,I want to draw Some Transparent Images By Using Draw method Of Graphics(From GDI PLUS).NOw to Draw On that Device Context,I need that DC.And the file in Which I am working doesnt contain any OnDraw or either am not able to get Handle of r that Display Window.
ANd Yes, Window is from my own application.

Regards
Yogesh

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