Amidakuji

amidakuji.rb

#!/usr/bin/env ruby
# Based on what N. Ishitobi and Y. Isozaki wrote at minatorubykaigi01.
# Modified by Y. Isozaki.

class Amidakuji

  def initialize(people, height=10)
    @people, @height = people, height
  end

  def draw
    draw_players
    draw_lines
    draw_winner
  end

  private

  def draw_players
    puts ' ' + players.join('   ') + ' '
  end

  def players
    %w[A B C D E F G H I J K L M N O P Q R S T U V W X Y Z][0..@people-1]
  end

  def draw_lines
    @height.times { draw_line }
  end

  def draw_line
    a = []
    while a.length < @people do
      (a << '|   ') while rand(2) == 0
      a << '|---'
      a << '|   '
    end
    a[@people-1] = '|'
    puts ' ' + a[0..@people-1].join
  end

  def draw_winner
    a = Array.new(@people, '   ')
    a[rand(@people)] = '!!!'
    puts a.join(' ')
  end

end

begin
  people = ARGV.shift.to_i
  raise '<number-of-people> must be between 1 and 26' unless people.between?(1, 26)
  height = ARGV.shift.to_i
  height = 10 unless height > 0
rescue
  abort("Usage: #{$0} <number-of-people> [<height>]")
end

amidakuji = Amidakuji.new(people, height)
amidakuji.draw