Roberts_abstractions is a project mainly written in C, it's free.
Eric S. Roberts' Programming Abstractions in C
I'm reading Eric S. Roberts' Programming Abstractions in C: A Second Course in Computer Science. Yea, I know, I've barely started two other C books. But my CSE214 class has taught me one thing: Java is not a language with which to learn data structures & algorithms. Even cperciva thinks so!
In order for the code samples to work, you need to run make in the book_code/unix-xwindows directory first. I'm using Clang 2.8, so I've modified the book's original Makefile accordingly and have rewritten Roberts' gccx wrapper script, now called roberts_clang. Symlink that into /usr/local/bin (or somewhere else that's in your PATH) and you're set.
I'm currently on page 39 (out of the 743 that I plan to read; Chapter 17, 'Looking Ahead to Java', is getting skipped). I'll be writing chapter notes on my blog, once it's set up.