Reverse Polish notation. During the 1970s and 1980s, RPN was known to many calculator users, as it was used in some handheld calculators of the time designed for advanced users: for example, the HP-10C series and Sinclair Scientific calculators. Most of what follows is about binary operators. A unary operator for which the reverse Polish notation is the general convention is the factorial.
Explanation[edit] Despite the name, reverse Polish notation is not exactly the reverse of Polish notation, for the operands of non-commutative operations are still written in the conventional order (e.g. "/ 6 3" in Polish notation and "6 3 /" in reverse Polish both evaluate to 2, whereas "3 6 /" in reverse Polish notation would evaluate to ½).
Practical implications[edit] In comparison testing of reverse Polish notation with algebraic notation, reverse Polish has been found to lead to faster calculations, for two reasons. Postfix algorithm[edit] The algorithm for evaluating any postfix expression is fairly straightforward: Evaluation of Prefix and Postfix expressions using stack. String Reference Page. C++ - Reverse polish notation interpreter/calculator. Data Structures Using C++: Using the Stack to create a RPN (post-fix notation) Calculator.