DaniWeb Forum Index > Software Development > C

C RSS

not getting non repeating random numbers many times

•

Join Date: Jul 2005

Posts: 4

Reputation: xshashiy is an unknown quantity at this point

Solved Threads: 0

xshashiy

Offline

Newbie Poster

not getting non repeating random numbers many times

Jul 6th, 2005

hi
i want to generate non repeated random numbers many times. for that i m using the following code.

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include "sys/types.h"
#include "stdio.h"
#define MAX 200
#define N 20
main()
{
	int array[N],r;
	int n = 0; int count_check,count_gen ,i,j;
 
	for(j=0;j<10;j++,printf("\n"))
	{
		srand(j);
		  for (count_gen=0;count_gen<=MAX;count_gen++)
		  {
		    r = rand()%N;
		    for ( count_check = 0; count_check < n; count_check++ )
		    {
		      if ( r == array[count_check] )break;
		    }// end for count_check.
		  if ( count_check == n ) array[n++] = r;
		  }// end for count_gen.
		for(i=0;i<N;i++)
		printf("%d\n",array[i]);
	}// end for j.
 
}//  end of main.
#include "sys/types.h"
#include "stdio.h"
#define MAX 200
#define N 20
main()
{
	int array[N],r;
	int n = 0; int count_check,count_gen ,i,j;

	for(j=0;j<10;j++,printf("\n"))
	{
		srand(j);
		  for (count_gen=0;count_gen<=MAX;count_gen++)
		  {
		    r = rand()%N;
		    for ( count_check = 0; count_check < n; count_check++ )
		    {
		      if ( r == array[count_check] )break;
		    }// end for count_check.
		  if ( count_check == n ) array[n++] = r;
		  }// end for count_gen.
		for(i=0;i<N;i++)
		printf("%d\n",array[i]);
	}// end for j.

}//  end of main.

<< moderator edit: added [code][/code] tags >>

it generates random numbers from 0 to 20 without repeating in an array. but it generates only once. next time in the for loop ( in j ) it gives the same pattern again , which i dont want. can some body please help me to get different pattern every time in the for loop ( for j ).

•

Join Date: Apr 2004

Posts: 4,342

Reputation: Dave Sinkula has a brilliant future

Solved Threads: 237

Dave Sinkula Dave Sinkula is offline

Offline

long time no c

Re: not getting non repeating random numbers many times

Jul 6th, 2005

Call srand once in a program, before the loop.

"One of the methods used by statists to destroy capitalism consists in establishing controls that tie a given industry hand and foot, making it unable to solve its problems, then declaring that freedom has failed and stronger controls are necessary." --Ayn Rand