All of these examples are in C , is it common for interviews to be conducted in C for major tech companies (assuming the job is not a C programming role)?
"I would never pick C because there is too much minutiae and not enough meat"
There's really not much minutiae at all when it comes to C. C++, sure, I'd agree, but not C.
You do have to be be pretty comfortable with how processors and memory work if you're going to be answering questions in C, but that aside the language's syntax, keyword usage and standard library are all quite small.
You spend half the time allocating memory, deallocating memory and checking error return values. I gave a couple hundred interviews at twitter, people that picked C wasted a ton of time not solving the problem.
A lot of higher level languages abstract away the fundamental implementation details and provide a lot more scaffolding than C.
So something that might be a couple of lines of Python or Ruby (just remember the library and the method calls), could wind up being a more interesting problem in C.
Easier to write your own answer once you've seen how the C works in a higher level language than to go in the other direction, assuming you need this material to begin with.