Because of the special symbol # which is not a direct part of the language (not belongs to ∑), we can identify which one is an original string and which is a reverse string.
So, in that case, all push and pop are cleared. Push all inputs before # and when we get inputs after # then pop all opposite match inputs which are present in the stack. If the stack is empty then the string is successfully accepted.
Now the stack is empty, then the string is accepted. So, it is a DCFL but we can write in this way ‘DCFL but not Regular’.