Random!!!

I can't figure out how to do random numbers!!!! I want to make a random # between 1 and 100, but It makes the number whatever it wants! How do I set a range, and make it so the random number is inputed into a variable?

FAQ!!! Nobody reads it, so we will keep seeing this question.

-Prelude

I read it, but I still don't understand them.

Thisis something I would like to know also, if someone could be so kind. :D

This is a random number generator I made because I was not satisfied by the one provided by Standard C/C++. :D

This one is automatically seeded after you declare the class object within your code and you simply have to call the random_tololot() function. :cool:

You can just hotwire the source like so:

PHP Code:

---

#include "random.cpp"

int main(void)
{
  RANDOM go;
  int num;
  
  /*...some other code...*/
  num = go.random_tololot(1, 1000);
  /*...some more code...*/

  return 0;
} 


---

I'm assume you know how to handle simple classes. If you do, then just fire away! :D

Hi,

Another option --

Code:

---

#include <stdio.h>
#include <stdlib.h>

int main()
{
        int i;
        int minumum = 1;
        int maximum = 100;

        srand(time(NULL)); /* seed randomizer with current time makes rand() rather more unique on each call*/
        i = minumum + (int)(rand()%maximum); /* simple but not recommended */
        /* i = minumum + (int)((double)maximum*rand()(RAND_MAX+1.0)); is better */
        printf("\ni is %d\n", i);
}

---

-Gerald

beg_g, I believe you must take the modulus as (max-min+1) to get the number in range. Otherwise you could have numbers outside the range.

Ex.

min = 98; max = 100; rand is 44
->rand % max = 44
->min + (rand % max) = 142

or

rand % (max-min+1) = 2
min + rand %(max-min+1) = 100

--Chorus

PS: depending on the random number generator, I believe you can lose "randomness" by taking modulus. You might be better off scaling the value into the appropriate range and truncating the mantissa.