auto publish posts with a condition of finding duplicate titles

Not sure if some one would have already asked this question:

I want to auto publish posts with a condition:

Example:

post 1 title name:
https://localhost/wordpress/this-is-sample-post/

when i am auto publishing post 2 with same title name “this-is-sample-post” it should check the database for duplicate title names and send post 2 to “pending review” or “draft” instead of auto publishing with https://localhost/wordpress/this-is-sample-post-2/

I believe this can be done with regular expression, but not sure where to start with, any ideas?