1 - Contact your university's career placement office. Get real chummy with them. Be very, very polite. they want you to get a good job, so you can afford to donate to the alumni associations.
2 - Contact your alumni associations, all of them. Get really, really chummy with them, until they realize you aren't donating any time soon. You want to go to events, meet fellow graduates that have been out there for a while and have opportunities, and you want them to remember you favorably.
3 - Find professional associations and get involved. Near first,then further away. Again, be real chummy, be a good guy, keep it simple, and admit you are looking for opportunities. NOT WORK. NOT A JOB. an OPPORTUNITY. New terminology.
4 - Find a job club in your area, possibly at the local Job Service or Employment Security office. You will be slumming with healthcare workers, salesmen, and laid-off union workers. They will teach you things you do not know, like how to actually write a resume, make an elevator speech, and interview.
5 - Above all, stay active, exercise, eat well, sleep. Keep yourself in shape, mentally and physically, to nail the next interview and hit the ground running.
Now, about that interview question. Me, I would have responded with "Wow, it's been a long time since freshman Computer Science, but let me see... I remember vector, pair, list, gee, I had to use valarray for a test, but it's been a while since I had to recite those. I've spent more time in {fill in your favorite high-level language here, unless it's VB6} for the past two years, but C is something like riding a bicycle. I don't remember every trick, but I can code whatever I need to, even if it means looking something up to jog my memory and get past a problem. What sort of C++ or C# work do you do here?"
Take the question, demonstrate familiarity with the subject, a partial answer with acknowledgment that you are not a walking encyclopedia, and then turn it around and ask about the apparent basis for the question - do they need a C++ guy, are they just scared you slept through that class, and can you both think on your feet and are interested in the requirements, how you will fit in, what's the real criteria here?
There are only three questions to be asked: Can you do the job? Will you do the job? And will you fit in?
Have ready answers to those.