Ask HN: How to learn as much about C or C++ in 3 days

This post is a follow-up question to to this one [1] I posted a couple of weeks ago.

Since I wrote the above post I have been asked to an interview for a position of Embedded Software Engineer. Apparently there is a lot of Assembly Language required, but as well as this they require C or C++ skills. They do understand I have no such experience with C or C++, but I don't wish to remain totally clueless, so are there any tutorials, reading materials out there that you could recommend I read over the next 3 days to give me some kind of useful knowledge?

Many thanks again for all help received so far, it is much appreciated.

[1]https://news.ycombinator.com/item?id=12231066