[QUIZ] Fractals (#125)

ruby-talk
21

Hi,
here is my solution. The fractal-part is straight forward, the ascii-art
was harder.

thanks,
Philip

···

--------------------------------

#!/usr/bin/ruby -w

class Fractal
  
  def initialize n
    @steps={:up =>[:up, :left, :up, :right, :up],
      :down=>[:down, :right, :down, :left, :down],
      :left=>[:left, :down, :left, :up, :left],
      :right=>[:right, :up, :right, :down, :right] }
    @n=n
    @moves=(0..n).to_a.inject([]) {|result, ignore| one_step(result) }
  end
  
  def to_s
    x=0
    y=0
    
    width = 3 ** @n
    height= (1+width)/2
    screen= (1.. height).collect { " " *(2* width-1) }
    
    @moves.each {|item|
      case item
        when :up
          y+=1
          (screen[y-1])[x-1]="|"
        when :down
          y-=1
          (screen[y])[x-1]="|"
        when :left
          x-=2
          (screen[y])[x]="_"
        when :right
          x+=2
          (screen[y])[x-2]="_"
      end
    }
    screen.reverse.join("\n")
  end

  private
  
  def one_step x
    x.empty? ? [:right] : (x.collect {|item| @steps[item] }).flatten
  end
  
end

n=ARGV[0].to_i

if (ARGV.length < 1 || n<0)
  puts "Usage: quizz_125.rb level"
  puts "-> level: non-negative integer"
else
  puts Fractal.new(n)
end