Using macro results in incorrect output when used as part of a larger math expression - why does this happen?

Question

This is a normal C routine program which i found out in some question bank. It is shown below:

#define CUBE(p) p*p*p

main()
{
    int k;
    k = 27 / CUBE(3         


        

Answer 1

Your macro is not protected. Try

#define CUBE(p) ((p)*(p)*(p))

The current macro was expanded to

k=27/3*3*3

which is ((27/3)*3)*3