Sha256: 752e8e4757cec317e1efb200ce855babb10e532448a88b1759e23e83154167a8

Contents?: true

Size: 718 Bytes

Versions: 14

Compression:

Stored size: 718 Bytes

Contents

module Hayde
  module Levenshtein
    # Based on the pseudocode in http://en.wikipedia.org/wiki/Levenshtein_distance.
    def self.distance(s1, s2)
      s = s1.unpack('U*')
      t = s2.unpack('U*')
      m = s.length
      n = t.length

      # matrix initialization
      d = []
      0.upto(m) { |i| d << [i] }
      0.upto(n) { |j| d[0][j] = j }

      # distance computation
      1.upto(m) do |i|
        1.upto(n) do |j|
          cost = s[i] == t[j] ? 0 : 1
          d[i][j] = [
            d[i-1][j] + 1,      # deletion
            d[i][j-1] + 1,      # insertion
            d[i-1][j-1] + cost, # substitution
          ].min
        end
      end

      # all done
      return d[m][n]
    end
  end
end

Version data entries

14 entries across 14 versions & 1 rubygems

Version Path
hayde-0.1.13 lib/hayde/levenshtein.rb
hayde-0.1.12 lib/hayde/levenshtein.rb
hayde-0.1.11 lib/hayde/levenshtein.rb
hayde-0.1.10 lib/hayde/levenshtein.rb
hayde-0.1.9 lib/hayde/levenshtein.rb
hayde-0.1.8 lib/hayde/levenshtein.rb
hayde-0.1.7 lib/hayde/levenshtein.rb
hayde-0.1.6 lib/hayde/levenshtein.rb
hayde-0.1.5 lib/hayde/levenshtein.rb
hayde-0.1.4 lib/hayde/levenshtein.rb
hayde-0.1.3 lib/hayde/levenshtein.rb
hayde-0.1.2 lib/hayde/levenshtein.rb
hayde-0.1.1 lib/hayde/levenshtein.rb
hayde-0.1.0 lib/hayde/levenshtein.rb