[[プログラミング言語/Ruby/コードリーディング]] #contents #br ----- **素数判定 [#u53871db] ま さ に 外 道(I) require 'mathn.rb' class PrimeDistincter def initialize @prime = Prime.new @cache = [] end def prime?(x) extend_cache x if @cache.empty? || x > @cache.last @cache.include? x end private def extend_cache(lim) @prime.each do |x| break if x > lim @cache.push x end end end #使用例 ppred = PrimeDistincter.new [1, 10, 2, 5, 7].each do |x| p ppred.prime?(x) end **素数を求める [#u934120e] ま さ に 外 道(II) require 'mathn.rb' def primes(lim) prms = [] prime = Prime.new prime.each do |x| break if x > lim prms.push x end prms end puts primes(100).join(" ") **うるう年測定 [#jd6b8ea7] require 'readline' module LeapYearDistincter LEAP_YEAR_JUDGE_TABLE = [ [ [true, false], [true, true] ], [ [], [] ] ] def leap_year?(y) f, h, fh = [4, 100, 400].collect{|x| (y % x).zero? ? 0 : 1 } LEAP_YEAR_JUDGE_TABLE[f][h][fh] or false end module_function :leap_year? end def recept_input while buffer = Readline.readline("Year? > ", true) yield buffer end end recept_input do |line| y = line.to_i if y >= 0 puts "#{y}: #{LeapYearDistincter.leap_year?(y)}" else puts "#{y}: invalid year." end end **ハノイの塔 [#wfd293b7] #Usage: ruby hanoi.rb [n number of disc] class Hanoi def initialize(n, h) @height = n @from = h[:from] @to = h[:to] @work = h[:work] end attr_reader :height, :from, :to, :work def each(&block) do_hanoi @height, @from, @to, @work, &block end private def do_hanoi(n, from, to, work, &block) if n == 1 yield n, from, to else do_hanoi n - 1, from, work, to, &block yield n, from, to do_hanoi n - 1, work, to, from, &block end end end ##使用例 num = (ARGV[0] || 3).to_i num >= 0 or raise "#{num}: Invalid Number" hanoi = Hanoi.new(num, :from => "A", :to => "B", :work => "C") hanoi.each do |n, from, to| puts "#{n}: #{from} -> #{to}" end **転置行列 [#hef0d150] require 'matrix' def parse_matrix(src) matrix = [] src.each do |line| line.chomp! next if line.empty? matrix.push line.split(/\s+/).map{|x| x.to_i } end Matrix.rows(matrix) end m = parse_matrix(ARGF.read) puts m.transpose.to_a.map{|v| v.join(" ") } **数当てゲーム [#j5d9808f] #Usage: ruby guess_number.rb [n Difficulty] srand require 'readline' def try_answer(prompt) while buf = Readline.readline(prompt, true) yield buf end end difficulty = (ARGV[0] || 1).to_i difficulty >= 1 or raise "#{difficulty}: Invalid difficulty direction" answer = rand(10 * difficulty + 1) judge_table = ["Collect!", "Bigger.", "Smaller."] try_answer("guess? > ") do |line| try = line.to_i result = try <=> answer puts "#{try} is #{judge_table[result]}" break if result.zero? end **数当てゲーム その２(Hit&Blow) [#d5c83be5] def help warn <<-HELP hit_and_blow.rb: play Hit & Blow game. usage: ruby hit_and_blow.rb [-option] [DIFFICULTY] h, --help show this help v, --version show version HELP exit 0 end def version warn "hit_and_blow 0.0.1" exit 0 end require 'readline' srand #n桁以下の数を乱数生成 def generate_answer(col) bottom = 10 ** (col - 1) rand(10 ** col - bottom) + bottom end #答えの数の妥当性チェック(全桁の数がユニークか) def valid_answer?(n) n.to_s.split(//).uniq! ? false : true end def generate_valid_answer(col) answer = nil loop do answer = generate_answer(col) valid_answer?(answer) and break end answer end #数を桁ごとに分ける(col指定で0補完) def num_split_cols(n, col=nil) width = col || n.to_s.length sprintf("%0#{width}d", n).split(//).map{|n| n.to_i } end def input_number(prompt) while line = Readline.readline(prompt, true) n = line.to_i if n < 0 warn "do not input negative number." else yield n end end end ARGV.delete_if do |x| case x when "-h", "--help" help when "-v", "--version" version end end n = (ARGV[0] || 4).to_i n > 0 or raise "#{n}: Invalid difficulty specification." answer = generate_valid_answer(n) answer_set = num_split_cols(answer, n) p answer if $DEBUG result = [] def result.clear(width) fill(0, 0, width) end def result.count(n) join.count(n.to_s) end result.clear(n) input_number("try! >") do |reply| reply_set = num_split_cols(reply, n) #check `Hit' reply_set.each_with_index do |r, i| result[i] += 1 if r == answer_set[i] end #check `Blow' reply_set.each_with_index do |r, i| result[i] += 1 if answer_set.include?(r) end hit, blow = result.count(2), result.count(1) print "#{hit} Hit & #{blow} Blow\n" break if hit == n result.clear(n) end **FizzBuzz [#jd36cc1e] def fizz_buzz(n) ret = "#{["Fizz"][n % 3]}#{["Buzz"][n % 5]}" ret.empty? ? n.to_s : ret end puts (1..100).collect{|n| fizz_buzz n } **カレンダー出力 [#c7b520e4] #使い方: コマンドラインにテキトーに日付を入れで動かす require 'optparse' require 'time' require 'forwardable' require 'stringio' class Month extend Forwardable [:Sunday, :Monday, :Thuesday, :Wednesday, :Thursday, :Friday, :Saturday].each_with_index do |const, n| const_set const, n end private def initialize(datum) @datum = datum @days = [nil] load_days datum, @days end def load_days(datum, days) 1.upto(31) do |day| date = Time.local(datum.year, datum.month, day) break unless date.month == datum.month days.push date end end public def_delegators "@datum", :year, :zone def name(abbrev=false) @datum.strftime(abbrev ? "%b" : "%B") end def_delegators "@days", :[], :first, :last def each @days.each{|d| yield d } end end class CalenderRender def initialize(mon) @mon = mon end def run(port=$stdout) weeks = calender_matrix(@mon) show_calender header_render(@mon) + calender_render(weeks) end private def show_calender(src, port=$stdout) port.print src end def calender_matrix(mon) weeks = [] week = Array.new(7) 1.upto(mon.last.day) do |n| week[mon[n].wday] = mon[n].day if mon[n].wday == Month::Saturday weeks.push week week = Array.new(7) end end weeks.push week weeks end end class CUICalenderRender < CalenderRender private def calender_matrix(mon) weeks = super weeks.unshift %w[Sun Mon Tue Wed Thu Fri Sat] weeks end def header_render(mon) col = 3 * 7 + (7 - 1) cap = "#{mon.name}, #{mon.year}" padding = (col - cap.length) / 2 head = sprintf("%#{padding}s%s%#{padding}s", "", cap, "") sprintf("%#{col}s\n", head) end def calender_render(weeks) weeks.collect{|week| if week.all?{|day| day.nil? } "" else week.collect{|day| sprintf("%3s", day.to_s)}.join(" ") end }.join("\n") end end class HTMLCalenderRender < CalenderRender def header_render(mon) h = "#{mon.name}, #{mon.year}" <<-HTML <!-- generated by calender.rb --> <?xml version="1.0" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>#{h}</title> </head> <body> <table> <tr> <th colspan="7">#{h}</th> </tr> HTML end def calender_render(weeks) buf = StringIO.new weeks.each do |week| buf.puts "\t<tr>" week.each do |day| buf.puts "\t\t<td>#{day}</td>" if day end buf.puts "\t</tr>" end buf.puts "</table>\n</body>\n</html>" buf.string end end class GUICalenderRender < CalenderRender #作成中 end render_class = CUICalenderRender render_class_table = { "cui" => CUICalenderRender, "gui" => GUICalenderRender, "html" => HTMLCalenderRender } op = OptionParser.new op.on("-m MODE", "--show-mode=MODE", "specify calender type(cui|gui|html)"){|v| render_class = render_class_table[v.downcase] || CUICalenderRender } op.on("-h", "--help", "show this help"){ warn op.help exit 0 } op.on("-v", "--version", "show version"){ warn "calender.rb 0.0.1" exit 0 } op.parse!(ARGV) if ARGV.size > 1 ARGV.replace [ARGV.join("/")] end datum = ARGV[0] ? Time.parse(ARGV[0]).getlocal : Time.now mon = Month.new(datum) render = render_class.new(mon) render.run **配列いじり [#w04579bf] def exclude_without_first!(array) fst = array.first.dup array.fill(0) array[0] = fst array end **Caesar暗号解読 [#gadcc14b] 総当り法による力任せ解読。 ### Usage: ruby caesar.rb HINT [CODE_FILE] module CaesarCode class CharTable def initialize(char_set) @char_set = char_set @shifted = char_set.dup @shift_count = 0 def @shifted.rotate temp = self.shift self.push temp self end @table = {} init_table end attr_reader :shift_count def [](key) @table[key] end def shift @shifted.rotate init_table @shift_count += 1 self end private def init_table @table.clear @char_set.zip(@shifted).each do |x| @table[x[0]] = x[1] end end end end def convert(base, table) base.split(//).collect{|x| table[x] or x }.join("") end raise ArgumentError, "hint word not given" if ARGV.empty? hint = ARGV.shift char_set = "abcdefghijklmnopqrstuvwxyz .,-".split(//) table = CaesarCode::CharTable.new(char_set) src = ARGF.read org = src[0] until src.include?(hint) src = convert(src, table.shift) raise "can't decode" if org == src[0] end print src print "鍵(シフト数)は #{table.shift_count} です\n" **ファイル読み込んで標準出力に出す [#l8316174] begin puts IO.readlines("kadai.txt").map{|line| "[#{line.chomp}]" } rescue => ex warn ex.message end **Base64 [#e59c345e] require 'stringio' def version warn "base64.rb 0.0.1" exit 0 end def help warn <<-HELP base64.rb: Base64 encoder/decoder usage: ruby base64.rb MODE [filenames ...] MODE: encode : ordinary file to Base64 format decode : Base64 format to original file none : print not convert one HELP exit 0 end proc_tbl = { :encode => proc{|org| [org].pack("m") }, :decode => proc{|org| org.unpack("m").first }, :none => proc{|org| org } } opt_mode = [] ARGV.delete_if do |x| case x when "encode", "decode", "none" opt_mode.push x.intern when "-h", "--help" help when "-v", "--version" version end end opt_mode.empty? and opt_mode.push :none opt_mode.size == 1 or raise "Too many mode specification" mode = opt_mode.first $stdin.binmode $stdout.binmode def argf_imitate(argv, mode) if argv.empty? yield $stdin else argv.each do |path| File.open(path, mode){|f| yield f } end end end argf_imitate(ARGV, 'rb') do |f| buffer = StringIO.new(proc_tbl[mode].call(f.read)) until buffer.eof? $stdout.print buffer.read(64) end end ---- **練習問題（アルゴリズム編） Ruby版 [#l15d170b] 問題の詳細については [[練習問題(アルゴリズム編)]]を参照。 **スタック [#b484c4bc] require 'readline' require 'forwardable' module RPCalc class Stack extend Forwardable def initialize @body = [] end def self.load(collection) stack = self.new collection.each{|x| stack.push x } stack end def_delegators :@body, :push, :pop, :size, :empty? def_delegator :@body, :last, :top def pretty_print ". " + @body.reverse.map{|x| x.to_s }.join(" ") + " ]" end end module Lexer def lex(str) str.strip.split(/\s+/) end end module Parser def parse(tokens) semantic_values = [] tokens.each do |token| case token when /\A[_a-zA-Z]\w*\Z/ semantic_values.push [token.intern, :IDENT] when /\A\d+\.\d+\Z/, /\A\d+\Z/ semantic_values.push [token.to_f, :NUMBER] when /\A(\+|-|\*|\/)\Z/ semantic_values.push [token.intern, :COPERATOR] else semantic_values.push [token.intern, :ETC] end end semantic_values end end module Evaluater def evaluate(svals, stack) svals.each do |value, type| case type when :COPERATOR unless o2 = stack.pop warn "Stack Empty." break end unless o1 = stack.pop warn "Stack Empty." stack.push o2 break end stack.push o1.__send__(value, o2) when :NUMBER stack.push value when :IDENT exit if value == :exit when :ETC ; #ignore else raise Exception, "unknown semantic value: #{type}" end end stack.top end end class Calculator include Lexer, Parser, Evaluater def initialize @stack = Stack.new end def shell(prompt, echo=true) while line = Readline.readline(prompt, true) yield line puts @stack.pretty_print if echo end end def calculate(expr) tokens = lex(expr) svals = parse(tokens) evaluate(svals, @stack) end end end calc = RPCalc::Calculator.new calc.shell("> ") do |line| puts calc.calculate(line) end print "\n"