Class: Boy2Man::Janken

Inherits:
Object
  • Object
show all
Defined in:
lib/Boy2Man/janken.rb

Overview

Returns the history of player’s hand.

Returns:

  • (Array) —

    the history of player’s hand

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Janken

Returns a new instance of Janken.



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# File 'lib/Boy2Man/janken.rb', line 38

def initialize
  @history = Array.new
end

Instance Attribute Details

#history ⇒ Array (readonly)

Returns the history of player’s hand.

Returns:

  • (Array) —

    the history of player’s hand



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# File 'lib/Boy2Man/janken.rb', line 35

class Janken
  attr_reader :history
  
  def initialize
    @history = Array.new
  end

  def history
    # retrun deep copy of history, to prevent history to be changed.
    Marshal.load(Marshal.dump(@history))
  end

  # @return [Array] resets history
  def reset
    @history.clear
  end

  # @return [String]
  def pon(hand)
    case hand
    when *HANDS
      # 先に手を決めておかないと後出しになる
      selected = case predict
      when "グー"   then "パー"
      when "チョキ" then "グー"
      when "パー"   then "チョキ"
      end
      @history.push hand
      selected
    else
    end
  end
  
  alias :hoi :pon
  alias :ぽん :pon
  alias :ほい :hoi

  private
  def predict
    possible_hands = Array.new

    if @history.length >= 3
      @history.each_with_index do |hand, i|
        # 最後に出されたと、その前の手から、次の手を予想する
        if hand == @history.last(2)[0] && @history[i+1] == @history.last
          possible_hands.push @history[i+2] if @history[i+2] != nil
        end
      end        
    end

    if possible_hands.empty? || (1 < @history.length && @history.length < 3)
      @history.each_with_index do |hand, i|
        # 最後に出された手から、次の手を予想する
        if hand == @history.last
          possible_hands.push @history[i+1] if @history[i+1] != nil
        end
      end        
    end

    possible_hands.empty? ? %w(グー チョキ パー).sample : possible_hands.sample
  end

end

Instance Method Details

#pon(hand) ⇒ String Also known as: hoi, ぽん

Returns:

  • (String) 


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# File 'lib/Boy2Man/janken.rb', line 53

def pon(hand)
  case hand
  when *HANDS
    # 先に手を決めておかないと後出しになる
    selected = case predict
    when "グー"   then "パー"
    when "チョキ" then "グー"
    when "パー"   then "チョキ"
    end
    @history.push hand
    selected
  else
  end
end

#reset ⇒ Array

Returns resets history.

Returns:

  • (Array) —

    resets history



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# File 'lib/Boy2Man/janken.rb', line 48

def reset
  @history.clear
end