Codeforces#294 Div2-A

gistfile1.rb

# http://codeforces.com/contest/519/problem/A
class Board
  WEIGHTS = { q: 9, r: 5, b: 3, n: 3, p: 1 }

  def initialize(lines)
    @pieces = lines.join.chars
  end

  def which_to_win?
    case
    when score('white') > score('black')
      'White'
    when score('white') == score('black')
      'Draw'
    else
      'Black'
    end
  end

  private

  def score(color)
    selector = (color == 'white') ? ('A'..'Z').to_a : ('a'..'z').to_a

    @pieces.select { |piece| selector.include? piece }.map do |piece|
      weight piece
    end.inject(0, :+)
  end

  def weight(piece)
    key = piece.downcase.to_sym

    WEIGHTS.key?(key) ? WEIGHTS[key] : 0
  end
end

lines = [].tap do |arr|
  8.times { arr << gets.chomp }
end

board = Board.new(lines)
puts board.which_to_win?