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for (int i = length - 1; i > -1 ; i--)
{
}
for (int i = length - 1; i >= 0; i--)
{
}
I always used to think the bottom way was slower then the top because i saw "i >= 0" as being two different checks being done on i.
For this reason I thought doing "i > -1" was better cause it was just one comparison... but today i just noticed that -1 might be an additional operation being done in each iteration of the for-loop like "...is i greater then (what is the negative of 1)".
So which is the faster way? :P
EDIT: Hmm maybe it still is the first way that is faster cause the negative number might be evaluated at compile-time?
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The difference between those two, if there is any, will never be noticeable by people. Write whichever way makes sense. Assuming that code is looping over an array or other collection, I would always write i >= 0 because i is the array index and 0 is the logical stopping point.
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FocusedWolf wrote: So which is the faster way?
So which is the faster way?
for (int i = length - 1; i >= 0; i--)
The processor has a comparison instruction that performs >= 0 in one step.
Either way there is not a lot of reason to optimize this type of code anymore as on modern processors most integer instructions (like compares) effectively take only 1 clock tick unless a branch mis prediction causes the pipeline to be emptied. In that case it depends on how long the pipeline is. Athlons/Athlon64 have pipelines of around 22 steps while Pentium IV chips have around 30 steps.
John
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How to get a dialog size by ID?
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I want to create a view by CFormView::Create(), set the Client area is in the function's fourth parameter, so I must know the view size.
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Do mean size of dialog ? What about GetClientRect() ?
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Basically what I'm trying to do is add the functionality to let the user select a JPEG background image for my game, as eye candy. MFC has functions for handling bitmaps but nothing for JPEGs or other image formats. I'd like to load a JPEG and convert it to a bitmap so that I can blit it as necessary. What is the best way to do this? I'd rather do it without tacking on a huge library to my program, if possible.
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Look at the GDI+ library.
If you are aiming only at Windows XP, it ships with the DLL.
Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke
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You can use of CImage class for load jpg file.
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CoffeeAddict19 wrote: I'd like to load a JPEG and convert it to a bitmap so that I can blit it as necessary.
If you use GDI+ it's pretty simple...
Gdiplus::Bitmap SrcBitmap(L"C:\\Images\\MyJPEG.jpg", FALSE);
HBITMAP hBitmap;
SrcBitmap.GetHBITMAP(Gdiplus::Color(0xFF,0xFF,0xFF), &hBitmap);
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CoffeeAddict19 wrote: I'd like to load a JPEG and convert it to a bitmap so that I can blit it as necessary. What is the best way to do this? I'd rather do it without tacking on a huge library to my program, if possible.
http://www.codeproject.com/bitmap/extendedbitmap2.asp
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Re
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Hello,
I need to write a simple program that does the following:
- Accept voice from microphone
- Determine the volume of the voice (programatically)
- Increase or decrease a variable based on the volume of the voice from the microphone.
I will appreciate any help in this regard. Please a source code supplied with it will also be very good.
Thanks alot.
Commickey
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OK, you have some demo's in the msdn, you have to search for SAPI (Speech API).
I don't remember where I saw that exactly, but searching for SAPI must help you. if you don't find it, pleaqse tell it to me, I suppose that in a couple of days I'll be able to send something that I must have stored in some backups at home.
Hope this helps.
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Hello Stuart,
I still cannot find it... can you help again as you said?
Greetings,
Commickey
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You could search here on CP for "record sound" for some source code.
Mark
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hello,
pls find me out why code is not work for solitaire game...
Thanks in advance.pls..
here is code:
#include<iostream>
using namespace std;
/*****CLASS PLAYING CARD*****/
class PlayingCard
{
private:
int rank;//integer 1-13
int suit;//integer0-3
char color;//red('r') or black('b')
public:
PlayingCard(int,int);
PlayingCard();
void display();
~PlayingCard();
const static int diamond;
const static int heart;
const static int spade;
const static int club;
};
/***** CLASS MAKING PILE OF CARDS*****/
class PileofCards
{
private:
PlayingCard *pile;//pointer to array of playing cards
int top;//last element added to array
int size;//no. of cards in pile
int position;//position of pile amongst others
public:
PileofCards(int,int);
~PileofCards();
PlayingCard Peek();
PlayingCard Remove();
void display();
void Add(PlayingCard);
bool IsEmpty();
bool IsFull();
};
/***** CLASS DECK OF CARDS*****/
class Deck
{
private:
PlayingCard *deck[52];
int size;
public:
Deck();
int getSize();
bool IsEmpty();
PlayingCard getCard(int i);
void Display();
PlayingCard removeCard(int i);
~Deck();
};
/*****CLASS SOLITIRE*****/
class Solitire{
private:
Deck deckofCards;
PileofCards shuffled;
public:
Solitire();
void shuffle();
void display();
};
Solitire::Solitire():shuffled(52,1)
{}
/*****INITIALIZING*****/
const int PlayingCard::diamond=0;
const int PlayingCard::heart=1;
const int PlayingCard::spade=2;
const int PlayingCard::club=3;
/*****CONSTRUCTOR PLAYING CARD*****/
PlayingCard::PlayingCard(int X,int Y)
{
rank=X;
suit=Y;
if(Y==0 || Y==1)
{
color='r';
}
else if(Y==2 || Y==3)
{
color='b';
}
else
{
cout<<"invalid suit,object not created"<<endl;
}
}
*****constructor="" overloaded*****=""
playingcard::playingcard()
{
}
="" *****destructor*****=""
playingcard::~playingcard()
{
}
="" pile="" of="" cards*****=""
pileofcards::pileofcards(int="" x,int="" y)
{
size="X;
position=Y;
pile=" new="" playingcard[size];
top="-1;//empty" array
}
=""
pileofcards::~pileofcards()
{
delete="" []="" pile;
}
="" *****is="" empty*****=""
bool="" pileofcards::isempty()
{
if(top="=-1)
{
cout<<"pile" empty"<<endl;
return="" true;
}
else
{
return="" false;
}
}
="" full*****="" pileofcards::isfull()
{
if(top="=size-1)
{
cout<<"sorry" cannot="" add="" since="" is="" full"<<endl;
return="" true;
}
else=""
{
return="" false;
}
}
="" *****adding="" playing="" card="" to="" the="" pile*****=""
void="" pileofcards::add(playingcard="" x)
{
if(!isfull())
{
pile[top+1]="X;
top++;
}
}
/*****REMOVING" from=""
playingcard="" pileofcards::remove()
{
if(!isempty())
{
top--;
}
return="" pile[top+1];
}
="" *****peeking="" top="" pileofcards::peek()
{
return="" [top];
}
="" *****display....playing="" card*****="" playingcard::display()
{
cout<<rank<<"="" "<<suit<<"="" "<<color<<endl;
}
="" deck*****=""
deck::deck()
{=""
int="" j="0;
for(int" i="1;i<=13;i++)
{
deck[j]=new" playingcard(i,playingcard::spade);
j++;
}
for(int="" k="1;k<=13;k++)
{
deck[j]=new" playingcard(k,playingcard::diamond);
j++;
}
for(int="" l="1;l<=13;l++)
{
deck[j]=new" playingcard(l,playingcard::heart);
j++;
}
for(int="" m="1;m<=13;m++)
{
deck[j]=new" playingcard(m,playingcard::club);
j++;
}
int="" size="52;
}
/*****DESTRUCTOR"
deck::~deck()
{
if(!isempty())
{
for(int="" deck[i];
}
}
}
else=""
{
delete="" deck;
}
}
="" *****get="" size*****="" deck::getsize()
{
return="" size;
}
="" empty....deck*****="" deck::isempty()
{
if(getsize()="=0)
{
return"
return="" false;
}
="" *****getcard*****="" deck::getcard(int="" j)
{
return="" *deck[j];
}
="" *****display....deck*****="" deck:display()
{
for(int="">display();
}
}
/*****REMOVE...DECK*****/
PlayingCard Deck::removeCard(int i)
{
PlayingCard temp;
temp=getCard(i);
delete deck[i];
if(!IsEmpty())
{
for(int j=i;j<size;j++)
{
deck[j]=deck[j+1];
}
}
size--;
return temp;
}
="" *****shuffle*****=""
void="" solitire::shuffle()
{
int="" i;=""
while="" (!deckofcards.isempty())
{
i="rand()%deckofCards.getSize();"
="" cout<<"remove="" card="" \n";
shuffled.add(deckofcards.removecard(i));
}
}
="" *****display...solitire*****="" solitire::display()
{
if(!shuffled.isempty())
{
shuffled.display();
}
}
="" *****display...pile="" of="" cards*****="" pileofcards::display()
{=""
int="" i="0;
while(i<=top)
{
pile-">display();
i++;
pile++;
}
cout<
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Sorry for that.. Thanks for remind me..
when I ran that code .. I got three error.. might be it from Deck..
Error 1 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
Error 2 error C2063: 'Deck::deck' : not a function
Warning 3 warning C4154: deletion of an array expression; conversion to pointer supplied
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Now everything is ok!No error anymore and I can run the program.
But it not work coz of warning.And if I debug the program,it said "Debug Assertion Failed!"and with "Expression:_BLOCK_TYPE_IS_VALID(pHead->nBlockUse)"
Here is part of code:
[pre]Deck::~Deck()
{
if(!IsEmpty())
{
for(int i=0;i
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I think error comes from destructor..mean warning!
Deck::~Deck()
{
if(!IsEmpty())
{
for(int i=0;i{
if(deck[i]!=NULL)
{
delete deck[i];
}
}
}
else
{
Code:
delete [] deck;
}
}
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Hi,
with the help of MSDN I wrote my own little (pure) Windows Service, that doesn't do anything. I also implemented the ability to install/uninstall this service in the service database. My problem now is, that if I want to start that service from the system control in windows it crashes with a well known error message like this: "The instruction at 0xnnnnnnn referenced memory at 0xnnnnnnn. The memory could not be written."
I then wrote a simple logging-function, which prints the status information about my service to a file. And when I look at this file it seems that all is correct. All things are initialized and so on. And I also get to that point where the service's main function takes place, that means I get to the point where the real work of the service should take place. But as I said before, the service crashes while trying to start it up. That's a little strange to me. Maybe someone encountered a similar problem before or can give me some hint or help. That would be very nice. I know this description is a little bit vague, but it's not that easy because I can't figure out WHERE my service crashes. That's in fact my problem 
Ah I forgot to mention, that I am using WinXP. Maybe that's important...
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maybe posting your code will help...
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
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