def isBalanced(s)
  brackets_map_opened = {"{"=>"}", "["=>"]", "("=>")"}
  brackets_map_closed = brackets_map_opened.invert
  brackets_stack = []

  s.chars do |char|
    bracket = (brackets_map_opened[char] || brackets_map_closed[char])
    next unless bracket
    
    open_bracket = brackets_map_closed[char]
    if open_bracket && open_bracket == brackets_stack.last
      brackets_stack.pop
    else
      brackets_stack << char
    end
  end

  brackets_stack.empty? ? "YES" :"NO"
end