Craftsmen | SDEQ419 | Practical Test

Implement a Reverse Polish Notation calculator in Python

Part (I) -- An RPN Calculator

Algorithm

1. Define stack
2. Read Tokens 
3. If token is operand push to stack
4. if token is operator then, b = pop(), a = pop() and apply according the operator
5. Run this process until token is finished
6. Print result

Part (II) -- An Infix to RPN Converter

Algorithm

1)Fixing the priority level for each operator. High to low order:
3.    - (negation)
2.    * /
1.    + - (subtraction)

2) If the token is an operand, do not stack it. Pass it to the output.

3) If token is an operator or parenthesis:
    3.1) if it is '(', push
    3.2) if it is ')', pop until we found '('
    3.3) push the incoming operator if its priority > top operator; else pop and popped stack item will
    be written into the output

4) Pop the remainder of the stack and write to the output (except left parenthesis)

How to run?

This package require Python3 to run. Follow the steps to run and use.

• Open up your terminal/console inside the project directory and type $ python main.py
• You'll get some instruction provided by the project. Just follow them.

How to run tests?

• Run for RPN Calculator python -m unittest rpn_calculator/tests.py
• Run for Infix to RPN Converter python -m unittest infix_rpn_converter/tests.py