What is RPN?
Mathematical operations are generally taught in infix notation, with the mathematical operators placed between the data that they operate on. For example, in the expression 2 + 3 = 5, the “+” operator is placed between the 2 and the 3. RPN (Reverse Polish Notation), invented by the Polish Mathematician Jan Lukasiewicz in 1920, is a way of expressing mathematical operations in postfix notation. Using the previous example, 2 + 3 = 5 would be expressed as 2E 3+ 5, where E denotes the Enter operator. Thus, in RPN all operators follow each data item and hence the term postfix. In the above example, the number of keystrokes is the same in both cases, four to obtain the answer 5. However, this is not always true. RPN makes it possible to enter data and operations without having to write down the intermediate answers or use parentheses. For example, the infix notation expression (3 + 4) * 6 = 42 requires 8 keystrokes to obtain the answer. In RPN, this would be 3E 4+ 6* 42. That is a saving of
Mathematical operations are generally taught in infix notation, with the mathematical operators placed between the data that they operate on. For example, in the expression 2 + 3 = 5, the “+” operator is placed between the 2 and the 3. RPN (Reverse Polish Notation), invented by the Polish Mathematician Jan Lukasiewicz in 1920, is a way of expressing mathematical operations in postfix notation. Using the previous example, 2 + 3 = 5 would be expressed as 2E 3+ 5, where E denotes the Enter operator. Thus, in RPN all operators follow each data item and hence the term postfix. In the above example, the number of keystrokes is the same in both cases, four to obtain the answer 5. However, this is not always the case. RPN makes it possible to enter data and operations without having to write down the intermediate answers or use parentheses. For example, the infix notation expression (3 + 4) * 6 = 42 requires 8 keystrokes to obtain the answer. In RPN, this would be 6 keystrokes: 3E 4+ 6*. That
