I've asked a question and then with the help of commenters I've found the answer. Should I close it/post the answer by myself or wait for other to post an answer?
Don't close the question. Instead:
(1)Why don't you first ask in a comment, for the commenter that helped you most, to post their comment as an answer, and perhaps fill in any missing details?
If more than one commenter helped you, or you asked the most helpful commenter to post and answer, and they choose not to:
(2) then by all means, you can post the answer you arrived at, with others' help, as an answer to your own question.
In that case, perhaps consider checking the "community wiki" box/option (located immediately below the right side of the answer field), to designate the solution/answer was a "community effort."