DouKaku?

Words = %w(program programist programistic programma programmar
           programmatic programmatically programmatist programmer)
class Array
  def index2(&block)
    j = nil or each_with_index{|x, i| j = i if yield x} and j
  end
end
class Trie
  def initialize(words)
    @words = words
    max = 0 and @words.each{|x| max = x.size if x.size > max}
    @trie = Array.new(max){Array.new}
  end
  def run
    @words.each{|str| add(str)}
    substitute
    puts rep(@trie)
  end
  def add(str)
    (ary = str.split(//)).size.times{|i|
      x, y = ary[i], (i < ary.size-1 ? ary[i+1] : nil)
      if (j = @trie[i].index2{|strc| strc[0] == x})
        @trie[i][j][1].index2{|char| char == y} ?
        next : @trie[i][j][1] << y
      else
        @trie[i] << [x, [y]]
      end
    }
  end
  def substitute #文字をインデックスに置換
    (@trie.size-1).times{|i|
      @trie[i].size.times{|j|
        trie = @trie[i][j][1]
        trie.map!{|x| @trie[i+1].index2{|y| x == y[0]}}.all?{|x| x} ?
        trie.sort! : trie.compact! && trie.sort!.unshift(nil)
      }
    }
  end
  private
  def rep(ary, i = 0)
    trie = ary[0][i]
    if ary.size == 1
      trie[0]
    else
      if trie[1].size != 1
        trie[0] + trie[1].map{|x|
          if x
            suffix = (x == trie[1].compact.max ? '?' : '|')
            "(#{rep(ary[1..-1], x)})#{suffix}"
          else
            ''
          end
        }.join
      else
        trie[0] + (trie[1][0] ? rep(ary[1..-1], trie[1][0]) : '')
      end
    end
  end
end
trie = Trie.new(Words)
trie.run