Binary search

binary_search.rb

def binary_search(number, random_numbers)
  middle = random_numbers.length / 2
  until random_numbers[middle] == number
    if random_numbers[middle] < number
      middle += random_numbers[middle..-1].length / 2
    end
    if random_numbers[middle] > number
      middle -= random_numbers[0..middle].length / 2
    end
  end
  middle
end