Having already done the preparatory work, the wise student normally don't need to get a complete solution. They already have the groundworks done, and are perfectly fine with getting a pointer about what error they have made, or what alternative solution they may have missed.

Since writing software is a question of putting together a large number of small, quite generic, LEGO pieces to form the required solution, a web forum can only really discuss individual LEGO pieces, or small sub-assemblies - whey they are good for, and important things about how they interact with other LEGO pieces or sub-assemblies. Most of the information about the LEGO pieces are already available either from the language manuals, the processor documentation or the web forum FAQs. At the sub-assembly level, the number of combinatorial choices increases a lot so a FAQ can't cover all alternatives. That opens up for discussions. Not the generic "What is a ring buffer", but specifics such as "Why is it advantageous to make the ring buffer size a factor of two?"