encode function

[sashazykov]

No description provided.

[sashazykov]

Ruby:

def compress(string)
  return "" if string.empty?
  _, head, tail = /(#{string[0]}+)(.*)/.match(string).to_a
  if head.size == 1
    "#{head}#{compress(tail)}"
  else
    "#{head.size}#{string[0]}#{compress(tail)}"
  end
end

compress("AAABBCCCCDEF")```