Loop.cr

loop.cr

struct Int
  def palindrome?
    self.to_s == self.to_s.reverse
  end
end

nums = Array(Int32).new.tap do |yielder|
  (100..999).each do |i|
    (i..999).each do |j|
      yielder << i * j
    end
  end
end.each

puts nums.select(&.palindrome?).max