Performance/memory usage difference?

Given two solutions:

[...]

Assuming that there are (a lot) more other members and methods in both classes (which are accessed within the class, not cross-class), and further assuming that the A class is being instantiated a *lot*: What would the runtime impact of these two approaches considering CPU time and memory used?

I would guess that solution 1 would be slightly more efficient, both memory and CPU-wise.

Correct; in solution 2 class A will need the parent pointer to resolve C at runtime.

Or am I overlooking something here where due to the nested stack frames of solution 1, the actual CPU or memory usage is higher than expected?

Doubtful.

/grubba