Experience shows that there is no need to be a genius to integrate. Knowing its course, namely exploit, avoid nonsense and show her physical sense enough.
This application, written by a contest examiner does not replace the course. It aims to give you
 - a practical understanding: how to approach the exercises
 - the minimum knowledge and expertise
 - the main pitfalls to avoid

On the practical side, you can review anywhere, sorting what you like: the application was thought to be effective!