Thread: Taking brackets into account for calculator input

Hi

I'm doing question 2 from http://olympiad.org.uk/papers/2006/bio/bio06-exam.pdf (Out of personal interest)

How can I write a program that can handle the brackets? I suppose a more general view would be:

a+b*c/d

I can easily write a program that does ((a+b)*c)/d that goes from left to right.

However, how could could I do a+((b*c)/d) that takes into account operator presedence (annoyingly my £5 calculator can do this, although I can't).

If I wrote in brackets e.g.

(a+b)*(c+d)

how could I write a program that knows which operations to do first?

Thanks!

You could take a look at the shunting yard algorithm, which really allows you to build a RPN/postfix string out of the expression, but should be adaptable to say building an expression tree or maybe even evaluating the expression.