From: dblack@...
Date: 2006-03-17T06:05:14+09:00
Subject: Re: Card tricks with Ruby

Hi --

On Fri, 17 Mar 2006, grrr wrote:

> So suppose you have a deck of cards, that might have some number of cards.
>
> First the cards are shuffled, in effect placed in random order.
>
> Then the deck is split, ie. some number of cards are lifted from the top
> of the deck and placed under the remaining cards.
>
> How would one implement this? I was thinking of using an array, but how to
> shuffle the deck, and how to split the deck?

You could do:

   def shuffle
     sort_by { rand }
   end

(Disclaimer: I haven't really followed the discussions of how random
this and other techniques for shuffling are.)

Here's a demo of how you might cut the deck (using a small deck here):

   irb(main):015:0> deck = *1..10
   => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
   irb(main):016:0> deck.concat(deck.slice!(0,5))
   => [6, 7, 8, 9, 10, 1, 2, 3, 4, 5]


David

-- 
David A. Black (dblack@wobblini.net)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

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