Hi Ludoviko,
Many of the chapters do have practical implementations. The source code is online in Python and Ruby:
https://github.com/egonschiele/grokking_algorithms
In the book, I go through the code line by line (I don't like it when tech books just have a page of code with no comments or explanation).
Target audience: see my answer here:
https://coderanch.com/t/665756/design/Grokking-Algorithms-python
Prerequisite: the only prereq is coding knowledge in one language. I use Python in the book, but you can read the book even if you don't know Python.
Exercises and solutions: YES! This book contains both.
Companion website: manning.com/bhargava