histgram.rb

class Checker
	attr_accessor :reguler_array
	def initialize
		string = gets.chomp
		ary = string.split("")
		@reguler_array = make_good_ary(ary)
	end

	def make_good_ary(array)
		_ary = array

		rtnAry =[]
		stack = ""
		_ary.each do |chr|
			if /\d/ =~ chr
				stack = stack + chr
			else
				unless stack == ""
					rtnAry << stack.to_i
					stack = ""
				end
				rtnAry << chr
			end
		end

		return rtnAry
	end
end

##############################
class Printer
	def self.printing(register)
		alphabets = [*"a".."z"]
		counts = Array.new(26,0)
		ary = [alphabets,counts].transpose
		hash = Hash[*ary.flatten]

		hash.merge!(register)

		hash.each do |key,val|
			print "#{key}\s#{val}\n"
		end
	end
end
##############################

class Parser
	attr_accessor :master_register
	def initialize
		@master_register={}
		@register_stack =[]
		@number_stack=[]  ## [number,flag]
	end

	def parse(chr)
		if chr.kind_of?(Fixnum) ##数字の場合
			@number_stack << [chr,false]
		else
			if /\w/ =~ chr ## 文字の場合
				char_patern(chr)
			elsif "\(" == chr ##"("の場合
				@number_stack.last[1] = true 
				@register_stack << {}
			elsif "\)" == chr ##")"の場合
				pair = @number_stack.pop
				back_parenthesis_petern(pair)		
			end
		end
		clear_register
	end


	def clear_register
		if @number_stack.length == 0
			_register = @register_stack[0]
			@master_register.merge!(_register) do |chr,regi_val,mas_val|
				regi_val + mas_val
			end
			@register_stack.clear
		end
	end

	def char_patern(chr)
		_var = set_var

		@register_stack << {} unless @register_stack.last
		_register = @register_stack.last 

		if _register.has_key?(chr)
			_register[chr] += _var
		else
			_register.store(chr,_var)
		end
	end

	def set_var
		_var = 1
		if @number_stack.length != 0
			pair = @number_stack.pop
			if pair[1]	
				@number_stack << pair
			else
				_var = pair[0] 
			end
		end
		return _var
	end

	def back_parenthesis_petern(pair)
		multi = pair[0]
		_register = @register_stack.last
		_register.each{|chr,cnt| _register[chr] = multi * cnt }

		marge_to_parent
	end

	def marge_to_parent
		if @register_stack.length > 1
			child = @register_stack.pop
			parent = @register_stack.last #こっちは参照
			parent.merge!(child) do |chr,child_val,parent_val|
					child_val + parent_val
			end
		end
	end
end
##--------main---------------
def main
	parser = Parser.new
	checker = Checker.new
	ary = checker.reguler_array
	ary.each do |chr|
		parser.parse(chr)
	end
	Printer.printing(parser.master_register)
end
main