C / C++ / MFC

31-Mar-07 6:53

How the f*** OMG | :OMG:

this is sickening.

void fun(int);
void main()
{
 int a ;
 a=3;
 fun(a);
}

void fun(int n)
{
	if(n==0)//orif(n==-1)
		exit(0);<--If I put this the ouput is nothing, but if I remove it, the idiot compiler is bypassing the condition (0>0),(-1>0).
	if(n>0)//3,2,1,0,-1
	{
		printf("\nTHERE!");
		fun(--n);
		printf("\n%d",n); //HOW THE **** the control comes here?!!!?? :((
		fun(--n);////HOW THE **** the control comes here?!!!?? :((

	}
	else
	{
		printf("\nHERE!");
	}

}

How 0,-1 can be > than 0? sh*t. I'm not on drugs! but WTF | :WTF:

mark,led,jeron,toxcct,david someone help! help!
without exit(0),it prints

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286? WOWW! Blush | :O

Re: HTF? :mad: [modified]

PJ Arends31-Mar-07 7:20

PJ Arends

31-Mar-07 7:20

First off, what is the output you are expecting? With the recursive calls you are making the output you are getting makes perfect sense.

You may be right
I may be crazy
-- Billy Joel --

Within you lies the power for good, use it!!!

_808631-Mar-07 7:58

31-Mar-07 7:58

Thanks Arends,
but why does it bypass this condtion when n =0, or -1

<br />
if(n>0) //(0>0) (-1>0) [after successive calls to --n & fun(n)]<br />
{<br />
  but still it comes here! why?  <br />
}<br />

I still can't get that point. Recursion makes multiple copies of the function? may be I'm missing this? it gets into the stack everytime we call it, so the context of "n" changes? I can somehow come around the point but still need some help to understand it. Please help dude.

-- modified at 14:06 Saturday 31st March, 2007

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286? WOWW! Blush | :O

PJ Arends31-Mar-07 12:07

PJ Arends

31-Mar-07 12:07

_8086 wrote:
but why does it bypass this condtion when n =0, or -1

It does not, the recursive function calls stop when n is zero or less.

I think your confusion is coming from what n is. You have to remember that a new n is created every time fun() is called, you are not using a single n.

I cleaned up your sample a bit, so lets step through it:

void fun(int n)                              // start with n = 3
{
   if (n > 0)                                // n is greater than zero
   {
      fun(--n);                              // n is now two, recursive call to fun(2)

        +void fun(int n)                     // start with n = 2
        |{
        |   if (n > 0)                       // n is greater than zero
        |   {
        |      fun(--n)                      // n is now one, another recursive call to fun(1)
        |
        |         +void fun(int n)           // start with n = 1
        |         |{
        |         |   if (n > 0)             // n is greater than zero
        |         |   {
        |         |      fun(--n)            // n is now zero, another recursive call to fun(0)
        |         |
        |         |         +void fun(int n) // start with n = 0;
        |         |         |{
        |         |         |   if (n > 0)   // n is not greater than zero
        |         |         |   {
        |         |         |      fun(--n)  // not called
        |         |         |      printf("%d\n", n);
        |         |         |   }
        |         |         +}               // exit fun()
        |         |
        |         |      printf("%d\n", n);  // n is zero - output "0"
        |         |   }
        |         +}                         // exit fun()
        |
        |      printf("%d\n", n);            // n is one - output "1"
        |   }
        +}                                   // exit fun()

      printf("%d\n", n);                     // n is two - output "2"
   }
}                                            // exit fun()

and repeat ad infinitum.

You may be right
I may be crazy
-- Billy Joel --

Within you lies the power for good, use it!!!

_808631-Mar-07 16:49

31-Mar-07 16:49

Excellent.

yourNewArtile* pjaRecursionArticle = (aritcle*) yourMessage; Big Grin | :-D

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286? WOWW! Blush | :O

CPallini31-Mar-07 12:08

CPallini

31-Mar-07 12:08

Of course the compiler is working fine. Please follow me in code inspection, to make analysis shorter, let's start with fun(2):

fun(2){
  if(2>0){
    fun(1);

At the moment (no output yet produced) we have to stop considering fun(2) and, due to recursion, procede with the inspection of fun(1):

fun(1){
  if(1>0){
    fun(0);

Again (no output yet), we have to suspend considering fun(1) and go deeper in recursion with fun(0):

fun(0){
  if(0>0){

Here, the compiler, that is a honest guy, correctly evaluates (0>0) as false and the function returns. Have we done? No, of course, there are (in the order) fun(1) and fun(2) waiting on the stack. So let's go back to fun(1) and reprise whereever we suspended:

  printf("\n%d",0);
  fun(-1);
}

As you can see, this is the first time we have a number on the console, and the number is 0 (you can also see that fun(-1) is called, but it will do nothing). Of course we could go on with code inspection, but I think it's enough: we have the zero, and we also have the demonstration that the compiler is not insane.

hope that:
(1) the analysis is correct.
(2) it helps.

Smile | :)

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.

_808631-Mar-07 16:51

ChttpConnection class problem

31-Mar-07 16:51

Thanks you very much Pallini Smile | :)

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286? WOWW! Blush | :O

prithaa31-Mar-07 6:31

31-Mar-07 6:31

Hello,

From where can I get the parameters which are required for
CHttpConnection class.
I basiacally want to get data from a remote computer .I have the IP address of the computer .Both the computers have internet access.
I have been through all the MFC iternet classes.But I do't understand from where these parameters be available.

CHttpConnection* GetHttpConnection( LPCTSTR pstrServer, INTERNET_PORT nPort = INTERNET_INVALID_PORT_NUMBER, LPCTSTR pstrUserName = NULL, LPCTSTR pstrPassword = NULL );

Prithaa

Mark Salsbery1-Apr-07 7:10

Mark Salsbery

1-Apr-07 7:10

Is this related to your ip address question below?

To get a file from a remote computer, the remote computer needs some kind of server to serve
you the file.

To use CHttpConnection there needs to be an HTTP server running on the remote computer.
To use CFtpConnection there needs to be an FTP server running on the remote computer.
etc.

Mark

"If you can dodge a wrench, you can dodge a ball."

prithaa1-Apr-07 20:09

1-Apr-07 20:09

Hello
Yes my problem is related to the ip address problem.
My remote computer is having an internet connection.
It does not have any server.

I thought ip address should be enough to recognize the PC on the Net.

If I am using a CDatabase class to access a remote computer's database then what kind of connection string should I provide.

Can you give me a link for the same.
I think there are many people on this site asking the same question.You can link me to that question if possible.

Prithaa

Mark Salsbery2-Apr-07 4:21

Mark Salsbery

2-Apr-07 4:21

Without some kind of "server" running on the remote machine (HTTP,FTP,SQL Server, etc.) then
an IP address isn't useful. There needs to be some application waiting for connections at the
given address (IP/Port).

Connection strings vary between databases - what database are you connecting to?

Mark

"If you can dodge a wrench, you can dodge a ball."

prithaa2-Apr-07 19:21

2-Apr-07 19:21

Hello,

Right now I am connecting to access database but soon I will have to connect to SQl server.

I have created an ODBC driver for my PC for access database but if I have the database on a remote computer then I will have add something in the network connections option of ODBC driver and provide a proper connection string in my CDatabase class isn't it?

But I don't know how to do the changes?

Prithaa

Mark Salsbery3-Apr-07 7:09

Mark Salsbery

3-Apr-07 7:09

I recommend using the SQL Native Client to connect.

Also download the SQL Server Books Online (BOL).

In that documentation is the following article - Using Connection String Keywords with SQL Native Client[^]

"If you can dodge a wrench, you can dodge a ball."

prithaa4-Apr-07 21:50