From: eden li <eden.li@...>
Date: 2007-04-23T12:15:43+09:00
Subject: Re: Shuffle Method

Why not just do a random sort instead?

>> some_array = ['cat', 'dog', 'fun', 'zoo']
=> ['cat', 'dog', 'fun', 'zoo']
>> some_array.sort { rand(3) - 1 }
=> ["zoo", "dog", "fun", "cat"]

On Apr 23, 8:59 am, Ari Brown <a...@aribrown.com> wrote:
> Once again, hello
>
> Normally I'd go to my dad for something like this. But since he's out
> and you all are hyperactive posters...
>
> I've been writing my own shuffling method, and I end up getting
> doubles in it.
> For instance, output might say something like:
> fun
> cat
> zoo
> zoo
>
> Now, it's NOT supposed to do that, but it does anyways. I am clueless
> as to what the problem is. What I DID notice, however (When using
> source 2) was that it seemed to pop off the last item in the array.
> Repeatedly. Yes, it's supposed to do that, but the last item changes
> each time. How does it keeping popping off, say, 'fun' repeatedly?
>
> Lotsa source code here, but I appreciate the help. Thanks
> ridonculously a lot.
>
> --------------------------------------------------------------|
> SOURCE 1
> --------------------------------------------------------------|
> some_array= ['cat', 'dog', 'fun', 'zoo']
>
> def shuffle some_array
>    recurssive_shuffle some_array
> end
>
> def recurssive_shuffle some_array
>    n = some_array.length
>    helper_array = []
>    new_array = []
>    while n != 0
>      r = rand(n)
>      while some_array.length != (r + 1)
>        helper_array.push some_array.pop
>      end
>      new_array.push some_array.pop
>      n = (n - 1)
>      helper_array.each do |item|
>        some_array.push item
>      end
>    end
>    puts new_array
> end
>
> shuffle some_array
> --------------------------------------------------------------|
> SOURCE 2
> --------------------------------------------------------------|
> some_array = ['cat', 'dog', 'fun', 'zoo']
>
> def shuffle some_array
>    recurssive_shuffle some_array
> end
>
> def recurssive_shuffle some_array
>    n = some_array.length
>    helper_array = []
>    new_array = []
>    while n != 0
>      r = rand(n)
>      while some_array.length != (r + 1)
>        helper_array.push some_array.pop
>        puts 'Array'
>        puts helper_array
>        puts
>      end
>      new_array.push some_array.pop
>      n = (n - 1)
>      helper_array.each do |item|
>        some_array.push item
>      end
>    end
>    puts new_array
> end
>
> shuffle some_array
>
> ---------------------------------------------------------------|
> ~Ari
> "I don't suffer from insanity. I enjoy every minute of it" --1337est
> man alive