Question

I have a set of tree objects with a depth somewhere in the 20s. Each of the nodes in this tree needs access to its tree’s root.

A couple of solutions:

1. Each node can store a reference to the root directly (wastes memory)
   • I can compute the root at runtime by ‘going up’ (wastes cycles)
   • I can use static fields (but this amounts to globals)

Can someone provide a design that doesn’t use a global (in any variation) but is more efficient that #1 or #2 in both memory or cycles respectively?

Edit: Since I have a Set of Trees, I can’t simply store it in a static since it’d be hard to differentiate between trees. (thanks maccullt)

Answer 1

Pass the root as a parameter to whichever functions in the node that need it.

Edit: The options are really the following:

1. Store the root reference in the node
2. Don’t store the root reference at all
3. Store the root reference in a global
4. Store the root reference on the stack (my suggestion, either visitor pattern or recursive)

I think this all the possibilities, there is no option 5.