Class: ABComputer

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

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ABComputer

Returns a new instance of ABComputer.



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# File 'lib/abcomputer.rb', line 2

def initialize

end

Instance Method Details

#get_max(depth, alpha, beta) ⇒ Object 



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# File 'lib/abcomputer.rb', line 22

def get_max(depth, alpha, beta)
  iterate_board do |row, column|
    if alpha > beta
      return alpha
    else
      if @board.is_empty_at(row, column)
        @board.move(row, column)
        if @observer.game_over?
         return -@board.player_value if @observer.has_winner?
         return 0
        else
         value = get_min(depth+1, alpha, beta)
         alpha = value if alpha < value
        end
      end
    end
  end
end

#get_min(depth, alpha, beta) ⇒ Object 



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# File 'lib/abcomputer.rb', line 41

def get_min(depth, alpha, beta)
  iterate_board do |row, column|
    if alpha < beta
      return beta
    else
      if @board.is_empty_at(row, column)
        @board.move(row, column)
        if @observer.game_over?
         return -@board.player_value if @observer.has_winner?
         return 0
        else
         value = get_max(depth+1, alpha, beta)
         beta = value if beta > value
        end
      end
    end
  end
end

#make_move ⇒ Object 



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# File 'lib/abcomputer.rb', line 6

def make_move
  alpha = (-1.0)/(0.0)
  beta = (1.0)/(0.0)
  best_score = nil
  iterate_board do |row, column|
    @board.make_move(row, column)
    path_score = get_max(1, alpha, beta)
    @board.undo_move
    if best_score.nil? || path_score > best_score
      best_row = row
      best_column = column
      best_score = path_score
    end
  end
end