文字列のサイコロ符号化(速度度外視)

convert.rb

# Usage: ruby convert.rb FILE

require 'zlib'

# サイコロの組み合わせ数
N = (2 + 4 + 4 + 2 + 2 + 4) * 3

def num2num_ary(num, base)
  num_ary = []
  while num != 0
    num_ary << num % base
    num = num / base
  end
  num_ary
end

def num_ary2num(ary, base)
  num = 0
  x = 1
  ary.each do |n|
    num += x * n
    x *= base
  end
  num
end

def to_dice(data)
  num2num_ary(('1' + data.unpack('b*')[0]).to_i(2), N)
end

raw = ARGF.read
compressed = Zlib.deflate raw

# 符号化
puts "size of compressed: #{compressed.size} (raw: #{raw.size})"

diced = to_dice(compressed)
puts "number of required dice: #{diced.size} (raw: #{to_dice(raw).size})"

# 復号化
decoded = Zlib.inflate [num_ary2num(diced, N).to_s(2)[1..-1]].pack('b*')
puts decoded