How to parse unary operator in reverse polish notation?

Question

Algorithms

Did OPN according to this article: https://m.habr.com/post/282379/. Everything is fine, but the algorithm does not work correctly with carbon monoxide negation. How to fix?

Answer 1

Everything is fine, but the algorithm does not work correctly with unary negation.

It is not designed to work with unary negation.
The easiest way is by introducing a special symbol for unary negation, which is different from other operators.
Otherwise, you will have to enter an additional state - whether the previous character was and whether it was an operator, and if so, then treat the operator '-' immediately following it as unary.

Answer 2

Add your operator or function, and process.
(Out of the box, OPN does not work with unary negation)