Collection of Challenges, not directly linked to 1 topic/concept. Not meant to be executed literally per se but mainly as inspiration! So feel free to vary it!
Even more challenges that may not be perfectly worked out yet, but feel free to use them as inspiration for your own work!
There are many sites on the Internet with challenging programming practice materials:
For example, look at
A platform where you can create all kinds of assignments in C# sorted by difficulty and topic!
Another example:
One site that has all kinds of (often mathematical) programming challenges on it is
Euler project 54 (called poker hands) has already been mentioned by software teachers as an example of a fun challenge. Other relevant Eulers: [[OIS11 en OIS12 - Project Euler challenges.pdf]]