am basically attempting to create a calculator using a class hierarchy - the basic function will be:

Convert the String representation into a list of Tokens

Convert the List of Tokens into Polish Notation

Calculate the result on the basis of Polish Notation

I also need to represent objects -

numbers operators and brackets.

Following this i need to convert to polish notation - using a shunting yard algorithm and then compute the answer.

I am ok with understanding the shunting yard but am unsure as to the class hierarchy part.

The precedence is - Addition and Subtraction have a precedence of 2, and Multiplication and Division have a precedence of 3.

I am assuming i need a filereader class and also classes to handle the different objects.

I also need help in creating my own stacks and queues.

Thanks