Amount of pseudo code in the thesis body I'm writing my undergraduate thesis (~25 pages) on a computer program I've developed. Naturally, I'm expected to explain what the program does and how it is implemented. However, the algorithm is quite complex and I simply cannot afford to include a full description.

What do you think, should I:


Lay out the general contours in writing and leave out the semi-obvious implementation details. The amount of detail should be enough to reproduce my work, but it would look rather vague and hard to read.
Include main pieces of the algorithm (written in pseudo code) in the body and use comments to explain what is going on. I'm leaning towards this one, as the work looks more readable this way. However, cumulatively these bits and chunks amount to 3.5 full pages of code.
Put pseudo code in the appendix. But in this case the major part of the explanation would be done in the appendix and the body would look kind of empty.
Use block diagrams

Block diagrams are effective for conveying the functionality of the program and abstracting away complex and/or banal code. For my dissertation (novel implementation of controller for exhaust gas recirculation), I used block diagrams to cover the overall functionality of my code and subsequent sections to explain non-trivial implementations. 

If you are not pressed for a page/word count and feel like the only way for the program to be understood is a full explanation: fully explain it. For the sake of the sanity of your reader, your second bullet point seems most prudent: Explain rather than disclose simple and obvious code in the main body and disclose it in the appendix. Novel code implementations should be disclosed and explained in the main body of the report.

For my undergraduate dissertation I opted for this method. For example, my code modelled the control system and a DC motor. The DC motor model was trivial and unoriginal (the governing differential equations can be derived or looked up easily) and so a simple mathematical explanation of the torque and armature current equations in the main body was sufficient.