Problems with Makefiles
Do not copy and paste Makefiles from the class web notes. Rather,
save the files using Edit/Save. The Makefiles are notoriously
sensitive to special characters which may not even be
visible. The compilation may not work sometimes because the TAB
character which is supposed to precede the compilation command
g++... is not present.
Later in the semester, when you will have to create your own
Makefiles, I recommend that you modify existing Makefile files (editing
the names inside) which is known to work, rather than typing in a
Makefile from scratch.