esm_doukaku_20151022

esm_doukaku_20151022.rb

require 'rubygems'
require 'bundler'
Bundler.require

SEATS_COUNT = 8

class Hi
  def initialize(input)
    @input = input
    @eating = @cooking = @just_entered = 0
  end

  def queue
    @input.each_char.map(&:to_i)
  end

  def execute!
    queue.each.with_index do |input, index|
      succ

      if enterable?(input)
        enter(input)
      else
        redo
      end
    end

    whole_str
  end

  def succ
    @eating  = @cooking
    @cooking = @just_entered
    @just_entered = 0
  end

  def enterable?(headcount)
    !!enterable_index(headcount)
  end

  def enter(headcount)
    index = enterable_index(headcount)
    @just_entered = (([1] * headcount) + [0] * (SEATS_COUNT - headcount)).rotate(-index).join.to_i(2)
  end

  def enterable_index(headcount)
    (whole_str + whole_str).index(/0{#{headcount}}/)
  end

  def whole
    @eating | @cooking | @just_entered
  end

  def whole_str
    "%0#{SEATS_COUNT}b" % whole
  end
end

def test(input, expect)
  if Hi.new(input).execute! == expect
    puts 'ok'
  else
    raise 'failed'
  end
end

test("3316", "11111110")
test("3342153", "11111111")
test("8", "11111111")
test("232624", "11110110")
test("1", "10000000")
test("224673432", "11111000")
test("123464334", "11111110")
test("44372332", "11111111")
test("2344", "11111111")
test("6448476233", "11111100")
test("4345174644", "11111111")
test("77743", "11111110")
test("2136524281", "10000000")
test("344373", "11100000")
test("434226", "11111111")
test("7433223", "11111110")
test("2246534", "11110111")
test("634", "11111110")
test("2222", "11111100")
test("2442343238", "11111111")
test("7243344", "11111111")
test("26147234", "10111111")
test("34424", "10011111")
test("6334", "11011111")
test("3828342", "11011110")
test("4431", "11110000")
test("2843212125", "11111111")
test("333336482", "11000000")
test("374", "11110000")
test("4382333", "11100111")

Gemfile

source 'https://rubygems.org'

gem 'activesupport', require: 'active_support/all'
gem 'pry-byebug'