RPN Calculator

Project 1: RPN Calculator

What You'll Build

A stack-based Reverse Polish Notation (RPN) calculator that reads expressions from stdin and evaluates them. A classic K&R exercise (Chapter 4) that ties together arrays, strings, and pointers.

Concepts Applied

• Arrays as a stack data structure
• String parsing and tokenization
• Pointer usage for string traversal
• Error handling for malformed input
• Modular function design

Example

$ echo "3 4 + 2 *" | ./rpn
14
$ echo "5 1 2 + 4 * + 3 -" | ./rpn
14

Content coming soon. This project will guide you through building an RPN calculator step by step, starting with a simple stack implementation and building up to a full expression evaluator with error handling.