doors.rb

require 'benchmark'

def count_factors(number)
  factors = (1..number).select { |n| (number % n).zero? }
  factors.count
end
  
def print_doors(n)
  i = 0
  array = (1..n)
  array.each do |door|
    puts "Door ##{door} is #{count_factors(door).even? ? "closed" : "open" }." #=> This is not.
  end
end


n = 8000
Benchmark.bm do |x|
  x.report { print_doors(n) }
  x.report do
    (1..n).each do |i| 
      puts "Door #{i} is #{i**0.5 == (i**0.5).round ? "open" : "closed"}" #=> This is optimized.
    end
  end
end