There are no C programs required! Problem 2 asks for a C expression, Problem 3 can be solved with a single expression, although you can also provide a little C code logic as well (for example, a few if statements).

It may certainly be useful to actually write programs to test your code! You can do this with any C compiler on any machine. The code required for both problems could be tested in a C++ program as well. Don't give us the entire program, we just want the expressions that answer the questions.