How can I solve this Tower Building problem?

Hello,
I am aware this might not fit C++ specifically, but I have nowhere else to ask this and I couldn't find it online in this format.

Given n cubes, each of a color and size, what is the tallest tower I can build with them such that no cube is on top of a smaller cube and that no 2 cubes of the same color touch.
Some cubes can be of the same size.

What is an optimal algorithm for this?
Thanks
Registered users can post here. Sign in or register to post.