gistfile1.rb

require "rubygems"
require "rbench"
require "set"

RANGE = (1..1000)
ARRAY = RANGE.to_a
SET   = Set.new(ARRAY)

WORST_CASE_COMPLEXITY = ARRAY.size + 1

RBench.run(500_000) do
  column :one,   :title => 'Array'
  column :two,   :title => 'Set'
  column :three, :title => 'Range'

  report "Which is fastest?" do
    one {   ARRAY.include?(WORST_CASE_COMPLEXITY) }
    two {   SET.include?(WORST_CASE_COMPLEXITY)   }
    three { RANGE.include?(WORST_CASE_COMPLEXITY) }
  end
end

__END__
                            Array |     Set |   Range |
-------------------------------------------------------
Which is fastest?          22.470 |   0.192 |   0.303 |