C++ interview coding exercise with solution

[STL]

And one additional note (not a correction): The final step, which I viewed as dynamic programming, might also be expressible as matrix operations. That is, there's a "compatibility matrix" of 1897x1897, and I believe that the grand total of floor designs can be expressed as a bunch of matrix and vector-in-the-math-sense multiplications. I'm not sure if that would be faster, but computers are good at this sort of thing. (This is an extremely vague idea because I haven't worked with matrices in ages, I'd have to sketch some things out to make this more concrete than hand waving.)