any?

require 'benchmark'


def div_by_2(n)
    n % 2 == 0 ? true : false
end

a = 0.upto(rand(31337))
b = 0.upto(rand(31337))

def method_a(a,b)
a.each do |aa|
    b.each do |bb|
       return  if div_by_2(aa ** bb - 1)
    end
end
end

def method_b(a,b)

a.each do |aa|
    b.any? do |bb|
        div_by_2(aa ** bb - 1)
    end
end

end


Benchmark.bm do |x|
    x.report { method_b(a,b) }
    x.report { method_a(a,b) }
end


# vpereira@linux-8njk:~> ruby t.rb
#       user     system      total        real
#   0.020000   0.000000   0.020000 (  0.019316)
#   0.000000   0.000000   0.000000 (  0.000010)