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Good webpage that explains how to use rand() and srand() correctly?

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Join Date: May 2008

Posts: 82

Reputation: riahc3 is an unknown quantity at this point

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riahc3

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Junior Poster in Training

Re: Good webpage that explains how to use rand() and srand() correctly?

#11

Dec 1st, 2008

I figured it out

Had to run the seed outside of the do-while loop. Worked great.

One last question: Do I have to run srand(time(0)); only once in the entire program or each time I run a function called "int numbergenerator" which returns the random number?

Ill explain with code

running srand(time(0)); once:

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
void main()
{ 
int num;
srand(time(0));
int=numbergenerator;
}
 
int numbergenerator()
{
int num;
char c; //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE TIMES AS A TEST
do
{
num=rand() % 4;
printf ("number %i",num);
getch(c);
while (c!="x"); //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE AS A TEST
return num;
}
void main()
{ 
int num;
srand(time(0));
int=numbergenerator;
}

int numbergenerator()
{
int num;
char c; //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE TIMES AS A TEST
do
{
num=rand() % 4;
printf ("number %i",num);
getch(c);
while (c!="x"); //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE AS A TEST
return num;
}

running srand(time(0)) each time

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
void main()
{ 
int num;
int=numbergenerator;
}
 
int numbergenerator()
{
int num;
char c; //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE TIMES AS A TEST
srand(time(0))
do
{
num=rand() % 4;
printf ("number %i",num);
getch(c);
while (c!="x"); //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE AS A TEST
return num;
}
void main()
{ 
int num;
int=numbergenerator;
}

int numbergenerator()
{
int num;
char c; //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE TIMES AS A TEST
srand(time(0))
do
{
num=rand() % 4;
printf ("number %i",num);
getch(c);
while (c!="x"); //DO NOT PAY ATTENTION TO THIS. IT IS JUST SO THE DO-LOOP DOESN'T END AND GENERATES INFINITE AS A TEST
return num;
}

Last edited by riahc3; Dec 1st, 2008 at 4:57 am.

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Join Date: Oct 2006

Posts: 2,968

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niek_e

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Cenosillicaphobiac

Re: Good webpage that explains how to use rand() and srand() correctly?

#12

Dec 1st, 2008

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Originally Posted by riahc3

Again this is for C++, not C.

I did not realize that you were unable to convert a command as cout to a command as printf .....

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Originally Posted by riahc3

It is obvious that you are a complete *******; Some are just starting out or simply need help to understand a certain area

I won't start a flamewar about the " ******* ".
If you're really trying to understand 'a certain area', you should really read the link I posted. I wasn't kidding, it's good info although there might be some C++ code involved.

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Originally Posted by riahc3

Thank you for posting this code. It works but my only problem is that (in a do-while loop) it generates 0 about 10-15 times then 3 another 10-15 times then 3 another 10-15 times then 2 another 10-15 times then 1 another 10-15 times then 0 again and all over again....

So you have an error in your code/logic. Post your code because I don't have a magic crystal ball and I can't se your code from here.

Last edited by niek_e; Dec 1st, 2008 at 4:59 am.

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Join Date: Oct 2006

Posts: 2,968

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niek_e

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Cenosillicaphobiac

Re: Good webpage that explains how to use rand() and srand() correctly?

#13

Dec 1st, 2008

•

Originally Posted by riahc3

One last question: Do I have to run srand(time(0)); only once in the entire program

Yes

[edit]
You might want to read this about using void main()

Last edited by niek_e; Dec 1st, 2008 at 5:00 am.

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Join Date: Sep 2004

Posts: 7,846

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Narue

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Senior Bitch

Re: Good webpage that explains how to use rand() and srand() correctly?

#14

Dec 1st, 2008

>I figured it out
It seems miracles do happen. Though through all your bitching and moaning about C++, you still don't seem to understand that srand and rand are used identically in both languages. They're a part of the C standard library and the C subset of C++.

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