1. Does backslash (\) have the special meaning only within a string or
character constant? What if we have

\/*abc*/

outside the character or string constants?

=> Yes. Backslash has the special meaning only within a string or
character constant. If it's outside of "..." or '... ', then you should
not interpret '\' differently. That is, the above comment should be
taken out after running your program (\/*abc*/ -> \).

2. Do we need to handle a logical line made up of multiple physical
lines? For example, should we convert

x = (a + b + \
c + d);

to

x = (a + b + c + d);

=> No. You can assume that each logical line consists of one physical
line for this assignment.