jsn · October 30, 2017 18:37
diff --git a/a.cr b/a.cr
 def check(l)
  abba = false
  l.scan(/([a-z])([a-z])\2\1/) do |rm|
    next if $1 == $2
    return false if rm.pre_match =~ /\[[^\]]*$/
    abba = true
  end
  !!abba
 end

 puts STDIN.each_line.select { |l| check l }.size
	def check(l)
	abba = false
	l.scan(/([a-z])([a-z])\2\1/) do \|rm\|
	next if $1 == $2
	return false if rm.pre_match =~ /\[[^\]]*$/
	abba = true
	end
	!!abba
	end

	puts STDIN.each_line.select { \|l\| check l }.size