You are a graduate student in theoretical mathematics, dabbling every so often in some interesting but equally useless computer science theory. From the beginning of the year, Professor Carl Hayden had agreed to help you with some research in exchange for grading some papers.
Or so you tell everyone. The truth is, both of you are in on a scheme to overthrow the dictatorial government. Unfortunately, he'd left you an (uncoded) message on the grading key yesterday:
I'm going to have to leave for a while. Another professor in the department seems to like to do research a little too far out of their field. I'd like to let you in on my ruminations, but this margin is a bit too small for that. I'll keep you posted when I find something.
Your hunches were right - there was a spy somewhere.
True to the message, he wasn't anywhere to be found today, leaving you and some other grad students to teach. As you walked into the classroom, you find that his computer was still on - and with a Word document titled "Lesson plans" typed up with the following:
MATH 4173 (graph theory) Problems 100, 105, 106, 107 (Algorithm book) CS 6369 (cryptography) Discuss key from last class Page 67 Problems 97, 114, 108 CS 6944 (advanced programming languages) Implement skipping whitespace between tokens Page 71 Problems 82, 112 Page 104 Problems 55, 70, 83 CS 4543 (programming languages I) Continue code from last class Purple book Page 114 Problems 69, 100 Page 160 Problems 72, 101, 114 Blue book Page 82 Problems 73, 78, 103
...which you found strange, because he has this terrible pet peeve of listing things like these in ascending order (or even by class number). And also because the only one of those classes he actually teaches is graph theory.
In another window, he has a webpage with all of the math professors' names:
You check the clock and decide that you still have some time before class starts. Unfortunately, the only book you have access to is the graph theory algorithms textbook. The section was a review (probably, the problems were so mixed up) and the chosen problems had the following graphs:
100:(full size at https://i.stack.imgur.com/QWK7Z.png)
After a few minutes of pondering and evidence-destroying, you know for certain who to be careful around as you organize your next attack.
Who is the spy?
(This is my first puzzle...any feedback is appreciated!)
You wonder if any clues under the "programming languages" classes might have something to do with esoteric programming languages; one of your closer fellow agents consistently complains about their being banned.
Prof. Hayden also has a habit of abbreviating "redundant" things. Like some problem numbers - if you're doing 71, 74, 75, and 77, he'll refer to them during class as problems 1, 4, 5, and 7.
OOC: TAGS!!! GOTTA HAVE SOME TAGS!!! And, again, the title actually is useful. Finally, since none of those are really hints, the "descriptions" before the problem listings actually help quite a bit with the solutions.