suffix array sample by ruby

suffixarray.rb

require "bsearch"               # http://0xcc.net/ruby-bsearch/index.html.en

class SuffixArray

  attr_accessor :word           # original string(String)
  attr_accessor :sary           # suffix array(Array)

  def initialize word
    @word = word
    @sary = Array.new(@word.size) {|i| i }
    @sary.sort! {|i, j|  @word[i..-1] <=> @word[j..-1] }
  end

  def search key
    i = @sary.bsearch_first {|x| @word[x, key.size] <=> key }
    @word[@sary[i], key.size]
  end

end

sary = SuffixArray.new 'abracadabra'
p sary
p sary.search('ra')

sary = SuffixArray.new 'mississippi'
p sary
p sary.search('ppi')