I got this puzzle from my neighbor. It was really easy to solve. Each of the smaller cubes is connected to the next one by an elastic string--kind of like a hair tie--on two sides except for the ends which are only attached on one side. The goal is to arrange the smaller cubes into the larger cube shape.

It's easy because you can proceed with a more-or-less greedy algorithm to get the solution. What I want to do though is to figure out how to represent the problem generically (4x4x4, different target configurations, different initial configurations, different component shapes, etc.), describe the state spaces for different configurations, and describe a generic algorithm for reaching the target configurations, and things like that.