From: Jeremy Hinegardner <jeremy@...>
Date: 2008-03-25T13:52:42+09:00
Subject: Re: generating unique random numbers

On Tue, Mar 25, 2008 at 10:24:54AM +0900, Chris Shea wrote:
> On Mar 24, 7:00 pm, Jimmy Palmer <modernfos...@gmail.com> wrote:
> > I'm trying to generate 8 unique random numbers between 1 and 13.
> >
> > for example my first set of results could be:
> >
> > 2, 8, 4, 6, 3, 10, 12, 1
> >
> > the results need to be between 1 and 13 and they must be unique.
> >
> > The rand(12) + 1 returns random numbers between 1 and 13, but they are
> > not unique.  Any quick solutions?
> > --
> > Posted viahttp://www.ruby-forum.com/.
> 
> Here's one more possibility:
> 
> numbers = (1..13).to_a
> randoms = []
> 8.times {randoms << numbers.delete_at(rand(numbers.size))}
> 
> Though, Tim's solution might be most readable.

You might also look through the solutions for Ruby Quiz #39 (Sampling).

http://rubyquiz.com/quiz39.html

there are couple of other ruby quizes where things like this are touched on.
You might browse through the archives.

enjoy,

-jeremy

-- 
========================================================================
 Jeremy Hinegardner                              jeremy@hinegardner.org