I'm studying Herstein's Topics in algebra and Hardy&Wright's An introduction to the theory of numbers, and I was wondering if there are some exercise books (that is, books with solved problems and exercises) that I can use as companions.
The books I am searching for should be:
- full of hard, non-obvious, non-common, and thought-provoking problems;
- rich of complete, step by step, rigorous, and enlightening solutions.
Roughly speaking, something similar (in some sense) to George Pólya and Gabor Szegő's Problems and Theorems in Analysis.