Shunting-yard Algorithm - A Simple Conversion

A Simple Conversion

Input: 3+4

1. Add 3 to the output queue (whenever a number is read it is added to the output)
2. Push + (or its ID) onto the operator stack
3. Add 4 to the output queue
4. After reading the expression pop the operators off the stack and add them to the output.
5. In this case there is only one, "+".
6. Output 3 4 +

This already shows a couple of rules:

• All numbers are added to the output when they are read.
• At the end of reading the expression, pop all operators off the stack and onto the output.