RO_2021_Q3.rb

class Race
  def initialize(racers)
    @racers = racers.map { |rc| rc.new }
    results = @racers.map { |_r| 1 }
    @racers.each do |r|
      r.set_turn_results(1, 1, results)
    end
    @goaled = []
  end

  def start!
    turn = 1
    loop do
      break if @racers.empty?

      @racers.each(&:run)
      @racers.sort_by! { |r| -r.position }

      puts '--------------------------------'
      puts "turn : #{turn}"
      @racers.each do |r|
        puts "#{r.class} => position:#{r.position}"
      end

      running = []
      @racers.each do |r|
        r.goal? ? (@goaled << r) : (running << r)
      end
      break if running.empty?

      rank = 1
      pos = 100
      results = []
      running.each.with_index(1) do |r, ind|
        rank = (pos > r.position ? ind : rank)
        results << rank
        pos = r.position
      end
      puts results.join(',')

      turn += 1
      running.zip(results).each { |r, rank| r.set_turn_results(turn, rank, results) }
      @racers = running
    end

    puts '-------- RESULTS -------'
    @goaled.each.with_index(1) do |r, rank|
      puts "#{rank} => #{r.class}"
    end
  end
end

class Racer
  attr_reader :rank, :position, :turn

  def initialize
    @rank = 0
    @position = 0
    @turn = 0
  end

  def goal?
    @position >= 100
  end

  def set_turn_results(turn, rank, results)
    @turn = turn
    @rank = rank
    @results = results
  end

  def run
    @position += move_value
  end

  private

  # need override
  def move_value
    0
  end
end

class GoRockstar < Racer
  private

  def move_value
    last? ? 7 : 0
  end

  def last?
    @results.max == @rank
  end
end

class Maruchan < Racer
  private

  def move_value
    @turn.odd? ? 3 : 0
  end
end

class Danriki < Racer
  private

  def move_value
    head_only? ? -2 : 4
  end

  def head_only?
    @rank == 1 && @results.select { |r| r == 1 }.size == 1
  end
end

class Syakariki < Racer
  private

  def move_value
    same_rankers
  end

  def same_rankers
    @results.select { |r| r == @rank }.size
  end
end

class Syaroku < Racer
  private

  def move_value
    head? ? 1 : 3
  end

  def head?
    @rank == 1
  end
end

class RinRin < Racer
  private

  def move_value
    @turn.odd? ? 5 : -2
  end
end

class Hijyousyoku < Racer
  private

  def move_value
    @power ||= 0
    @power += (head_only? ? -4 : 1)
    @power
  end

  def head_only?
    @rank == 1 && @results.select { |r| r == 1 }.size == 1
  end
end

class TimeX < Racer
  private

  def move_value
    @turn.modulo(5).zero? ? 9 : 0
  end
end

race = Race.new(
  [
    GoRockstar,
    Maruchan,
    Danriki,
    Syakariki,
    Syaroku,
    RinRin,
    Hijyousyoku,
    TimeX
  ]
)

race.start!