Fixing printf modifiers

[Zacharyprime]

This produces warning(s)

The $ is a valid "operator" for printf, so I dug around to make sure this wasn't intentional, maybe there is some C++ trickery I hadn't seen before. I couldn't find any reference that uses $ this way.

I also noticed after the fact that in the same file the identical expression exists but with % as I would have expected, so I'm certain it's a typo.

[Zacharyprime]

For the second printf fix:
%d is not the correct printf modifier for size_t
%zu and %zd are the valid ones to use in this case.

%zu is the one that is recommended for size_t