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random number

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Join Date: Nov 2007

Posts: 146

Reputation: emilio is an unknown quantity at this point

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emilio

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Junior Poster

random number

May 1st, 2008

i am trying to generate random numbers in a loop
i wrote this function

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
 int getRand ( int a , int b ) 
{
static int x = 0 ;
 
if ( x == 0 ) {
 
  srand ( time( NULL ) ) ;
 
 x++ ;
 
  }
 
  return a+rand()%(b-a+1);
}
 int getRand ( int a , int b ) 
{
static int x = 0 ;

if ( x == 0 ) {
 
  srand ( time( NULL ) ) ;

 x++ ;

  }

  return a+rand()%(b-a+1);
}

but every time i use it in a loop i get the same number

Last edited by emilio; May 1st, 2008 at 12:53 pm.

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Join Date: Sep 2004

Posts: 7,867

Reputation: Narue has a reputation beyond repute

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Narue

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Senior Bitch

Re: random number

May 1st, 2008

Post the code that calls getRand.

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Join Date: Nov 2007

Posts: 146

Reputation: emilio is an unknown quantity at this point

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emilio

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Junior Poster

Re: random number

May 1st, 2008

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
for(i=0 ; i<5 ; i++)
{
chid = fork();
if (chid == 0)
   {
    n = getRand(0,9);
    printf("child number %d goes to sleep for %d seconds\n",i+1,n);
    sleep(n);
    kill(getpid(),SIGKILL);
   }
}
for(i=0 ; i<5 ; i++)
{
chid = fork();
if (chid == 0)
   {
    n = getRand(0,9);
    printf("child number %d goes to sleep for %d seconds\n",i+1,n);
    sleep(n);
    kill(getpid(),SIGKILL);
   }
}