There is, essentially, nothing to be known about C beyond what is in this book. If you can read those 272 pages, and understand them all, then you are well on the way to being a C wizard. Say what? This is like saying that once you know what all the commands in Illustrator do, you're well on your way to being a professional illustrator. The reason that K&R is so small is that so much of C programming happens outside/…
Read a good algorithms text to learn about balanced trees. Once you understand what one is, you ought to have learned enough about C from K&R to be able to implement one in C.