The correct answer depends on you. Things to consider:

• Does it work correctly?
• Do you understand it?
• Would anyone else understand it?
• Will you understand it in a month's time?
• Does it strike a good balance between terseness and verbosity?
• Could you make changes to it without it being likely to break in unforeseen ways?
• and a very distant last: Is it fast enough?

If you can answer yes to all those questions you can consider the code to be correct.