From: Ruby Quiz <james@...>
Date: 2005-11-18T22:31:18+09:00
Subject: [QUIZ] Euchre Hands (#55)

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The card game of Euchre has an unusual ordering of cards in the hand.  This
week's Ruby Quiz is to take a random Euchre hand and sort it.

The first thing you need to know is that Euchre is played with a small deck of
cards.  Four suits are used Diamonds (d), Clubs (c), Spades (s), and Hearts (h),
but each suit has only the cards Nine (9), Ten (T), Jack (J), Queen (Q), King
(K), and Ace (A).  The cards are generally ordered as I just listed them, Nine
being the low card and Ace the high card.  The exception is the "Bowers".

When a Euchre hand is started, the first task is to select a Trump suit.  How
that's done is not important, just know that one suit is always different from
the rest.  Trump is the best suit, valued higher than the other three suits
(which are basically equal).  In the Trump suit, the card order changes.

The first oddity of Trump is that the Jack of the selected suit becomes the
Right Bower, the highest ranked Trump card.  The second oddity is that the other
Jack of the same color (Diamonds and Hearts are red while Clubs and Spades are
black) becomes the Left Bower, the second highest Trump card.  This card is
considered to be of the Trump suit for the rest of the hand.  For example, if
Spades is selected as Trump, the order of Spades becomes (lowest to highest): 
9s, Ts, Qs, Ks, As, Jc, and Js.  All other suits run Nine to Ace, save that
Clubs will be short a Jack.

The three non-Trump suits are equal, but it is good interface to sort the by
suit alternating red, black, red, and black, I think.  Especially with a GUI,
this makes it easier to understand the hand.

Input (on STDIN) will be a line containing the Trump suit, followed by five
lines containing a Euchre hand. For example:

	Diamonds
	Kc
	Jh
	Kd
	Td
	Ah

Your script should output (to STDOUT) the Trump suit, followed by the cards in
sorted order (highest card first):

	Diamonds
	Jh
	Kd
	Td
	Kc
	Ah

Here's a script that will feed your program random hands:

	#!/usr/local/bin/ruby -w
	
	# build a Euchre deck
	cards = Array.new
	%w{9 T J Q K A}.each do |face|
	  %w{d c s h}.each do |suit|
	    cards << face + suit
	  end
	end
	
	# choose trump
	puts %w{Diamonds Clubs Spades Hearts}[rand(4)]
	
	# deal a hand
	cards = cards.sort_by { rand }
	puts cards[0..4]

One last thought:  If accuracy is our ultimate goal here, how will you know your
output is correct?