Thread: random number

Read the FAQ.

And make sure that you only call srand( ) once, at the start of your program. If you have it within the function, it is rather pointless.

Originally posted by mrukok
but thats all in C

Generating the number is the same in C++. Just because it uses printf()'s and such, doesn't mean you can't swap them for their cout equivalents.

Originally posted by mrukok
but im easily confused!

Code:

#include <iostream.h>  
#include <stdlib.h>  
#include <time.h>  

int main(void)
{
  int i;
  
  srand(time(NULL));
  
  i = rand();
  
  cout << "Your random number is  << i << endl;  

  cout<< "This compiler can generate random numbers from 0 to " <<  RAND_MAX;

  return(0);
}

Code:

#include <iostream.h> 
#include <stdlib.h> 

int GetRand(int min, int max);

int main(void)
{
  int i, r;
  
  for (i = 0; i < 20; i++)
  {
    r = GetRand(10, 12);
    cout <<  "Your number is " <<  r << ' ';
  }
  
  return(0);
}

int GetRand(int min, int max)
{
  static int Init = 0;
  int rc;
  
  if (Init == 0)
  {
    /*
     *  As Init is static, it will remember it's value between
     *  function calls.  We only want srand() run once, so this
     *  is a simple way to ensure that happens.
     */
    srand(time(NULL));
    Init = 1;
  }

  /*
   * Formula:  
   *    rand() % N   <- To get a number between 0 - N-1
   *    Then add the result to min, giving you 
   *    a random number between min - max.
   */  
  rc = (rand() % (max - min + 1) + min);
  
  return (rc);
}

Or similar

>>#include <iostream.h>
>>#include <stdlib.h>
>>#include <time.h>

tsk tsk tsk

Code:

#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;