Leave it on stack or put in on heap?

The two are not even remotely identical. The second one uses the same buffer for all calls, the first uses a new buffer, meaning that the second is not thread-safe.

There is no penalty for putting data on the stack because you are just decrementing the stack pointer.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.