creating a random number within a desired range in visual c++...how?

[piski]

I need to generate a random number between 1 and 13. Its a random card dealing program. i tried to use rand() but it need the library stdlib and when i included that, the compiler said that it couldnt find it. what should i do?

 

[DaveSimmons]

are you including like this

#include <stdlib.h>

 

[piski]

no
#include <stdlib>
using namespace std;

 

[piski]

ok. i guess for some reason stdlib.h worked. however. when i say
cout << rand() it keeps showing 41. How can i give it parameters like between 1 and 13? I believe its RAND_MAX....
thanks

 

[DaveSimmons]

stdlb is a C standard library not the C++ STL

In the friendly Books Online:

"The rand function returns a pseudorandom integer in the range 0 to RAND_MAX. Use the srand function to seed the pseudorandom-number generator before calling rand."

So:
1. seeding the generator -- Books Online sample code shows you how to do this using the time function

2. limiting values to a range. Hmmm, what does % do? (Hint 2: then add +1)

 

[piski]

what does seed mean? initialize?

 

[DaveSimmons]

Originally posted by: piski
what does seed mean? initialize?

Yes. Pseudo random number generators take the initial value and use it to create all following values.

In CS a seed = starting / initial value or state, since future values or states "grow" out of it.