RPN Calculator

A reverse Polish notation (RPN) calculator. You type a normal infix expression (e.g. 3 + 4 * 2) and the program converts it to RPN internally, prints the converted expression, and shows the result.

Project layout

.
├── Module/
│   └── ReversedPolishNotation.java   # infix → RPN converter + evaluator
└── src/
    ├── Main.java                     # entry point (interactive loop)
    └── Calculator.java               # math operations (binary + unary)

All classes are in the RPNsimpleCalculator package.

Requirements

• Java 8 or newer (JDK with javac)

How to compile

From the project root:

javac -d out src/Main.java src/Calculator.java

If you also want to compile the Module classes:

javac -d out src/Main.java src/Calculator.java Module/ReversedPolishNotation.java

How to run

java -cp out RPNsimpleCalculator.Main

Example session

	------RPN Calculator-------

Type a normal arithmetic expression, e.g.  3 + 4 * (2 - 1)
Functions: sin cos tan log ln exp sqr sqrt inv abs
Type 'quit' to exit.

> 3 + 4 * 2
RPN:    3 4 2 * +
Result: 11.0

> (1 + 2) * (3 - 1)
RPN:    1 2 + 3 1 - *
Result: 6.0

> sqrt(16) + 9
RPN:    16 sqrt 9 +
Result: 13.0

> quit
Bye!

What you can type

Input	Example
Numbers (integers and decimals)	3.5
Operators	+ - * / % ^
Parentheses	(1 + 2) * 3
Functions	sin cos tan log ln exp sqr sqrt inv abs

Operator precedence is respected (^ > * / % > + -), and ^ is right-associative (2 ^ 3 ^ 2 = 512).

Notes

• Tokens are whitespace-separated, so write spaces around operators and parentheses: 3 + 4 * 2, not 3+4*2.
• Division by zero and invalid function input (e.g. sqrt(-1), log(0)) print an error message.
• tan works in degrees.