gistfile1.txt

require 'benchmark'
 
short_array = [1, 2, 3, 4, 1, 2, 5, 6]
long_array = ([1] * 1000) + short_array
short_match = [1, 2, 5]
long_match = short_match * 10
 
class Array
  def find_sub_1(match)
    (each_cons(match.size).with_index.find {|x, i| x == match } || []).last
  end
 
  def find_sub_2(match)
    (size - match.size).times.find do |i|
      match.each_with_index.all? {|e, j| self[i + j] == e }
    end
  end

  def find_sub_3 match
    0.upto(self.length-match.length) do |i|
      catch :fail do
        0.upto(match.length-1) do |j|
          throw :fail unless self[i+j] == match[j]
        end
        return i
      end
    end
    nil
  end
end

Benchmark.bmbm do |b|
  b.report('arrays') do
    1000.times { long_array.find_sub_1(long_match) }
  end
 
  b.report('algorithm') do
    1000.times { long_array.find_sub_2(long_match) }
  end

  b.report('pierre') do
    1000.times { long_array.find_sub_3(long_match) }
  end
end