Reverse polish notation

Reverse polish notation (RPN) is a method for describing arithmetic operations, popularized by the HP-35 calculator in the 1970s. Unlike infix notation, which puts the operator between two operands (e.g., 5 + 12), RPN puts the two operands first followed by the operator (e.g., 5 12 +).

Provide two examples of the usage of the Stack data structure in programming. These should be realistic examples