array.rb

require 'ruby-prof'

class Array

  def a_slice_exists? ary
    raise ArgumentError unless Array === ary
    each_index.select {|i| at(i) == ary[0]}.any? {|i| self[i,ary.length] == ary}
  end

  def b_slice_exists? slice
    start = slice.first
    len = slice.size
    each_with_index do |e, i|
      return true if e == start && self[i,len] == slice
    end
    false
  end

  def c_slice_exists? slice
    each_cons(slice.length).any? {|ary| ary == slice}
  end

end

A = [1,2,3,4,5]
B = [2,3,4]

RubyProf.start
1000.times { A.a_slice_exists? B }
result = RubyProf.stop
printer = RubyProf::FlatPrinter.new(result)
printer.print(STDOUT)

puts "------"

RubyProf.start
1000.times { A.b_slice_exists? B }
result = RubyProf.stop
printer = RubyProf::FlatPrinter.new(result)
printer.print(STDOUT)

puts "------"

RubyProf.start
1000.times { A.c_slice_exists? B }
result = RubyProf.stop
printer = RubyProf::FlatPrinter.new(result)
printer.print(STDOUT)

gistfile1.txt

Thread ID: 70125953113060
Fiber ID: 70125957549420
Total: 0.024274
Sort by: self_time

 %self      total      self      wait     child     calls  name
 32.51      0.011     0.008     0.000     0.003     2000   Array#each_index
 15.46      0.023     0.004     0.000     0.019     1000   Array#a_slice_exists?
 11.14      0.003     0.003     0.000     0.000     5000   Array#at
 10.34      0.004     0.003     0.000     0.002     1000   Array#each
  5.73      0.012     0.001     0.000     0.011     1000   Enumerable#select
  5.33      0.005     0.001     0.000     0.004     1000   Enumerable#any?
  5.27      0.024     0.001     0.000     0.023        1   Integer#times
  5.10      0.011     0.001     0.000     0.010     1000   Enumerator#each
  3.57      0.001     0.001     0.000     0.000     1000   Array#==
  3.06      0.001     0.001     0.000     0.000     1000   Array#[]
  2.38      0.001     0.001     0.000     0.000     1000   Module#===
  0.11      0.024     0.000     0.000     0.024        1   Global#[No method]

* indicates recursively called methods
------
Thread ID: 70125953113060
Fiber ID: 70125957549420
Total: 0.011421
Sort by: self_time

 %self      total      self      wait     child     calls  name
 28.58      0.005     0.003     0.000     0.002     1000   Array#each
 27.21      0.010     0.003     0.000     0.007     1000   Array#b_slice_exists?
 13.93      0.006     0.002     0.000     0.005     1000   Enumerable#each_with_index
 10.87      0.011     0.001     0.000     0.010        1   Integer#times
  7.43      0.001     0.001     0.000     0.000     1000   Array#==
  6.67      0.001     0.001     0.000     0.000     1000   Array#[]
  5.20      0.001     0.001     0.000     0.000     1000   Array#first
  0.10      0.011     0.000     0.000     0.011        1   Global#[No method]

* indicates recursively called methods
------
Thread ID: 70125953113060
Fiber ID: 70125957549420
Total: 0.015243
Sort by: self_time

 %self      total      self      wait     child     calls  name
 24.44      0.007     0.004     0.000     0.003     1000   Array#each
 17.00      0.009     0.003     0.000     0.007     2000   Enumerable#each_cons
 15.06      0.003     0.002     0.000     0.001     2000   Array#==
 14.70      0.014     0.002     0.000     0.012     1000   Array#c_slice_exists?
  8.39      0.011     0.001     0.000     0.009     1000   Enumerable#any?
  8.16      0.015     0.001     0.000     0.014        1   Integer#times
  7.87      0.009     0.001     0.000     0.008     1000   Enumerator#each
  4.30      0.001     0.001     0.000     0.000     1000   Fixnum#==
  0.08      0.015     0.000     0.000     0.015        1   Global#[No method]

* indicates recursively called methods