- Set Theory - never used this at all.
- Combinatorics - good basis for statistics, probability, cryptography.
- Graph Theory gets used all the time.
additional:
- Number Theory is pretty fun, in the sense that you don't need a computer
- Game Theory always fun.
- Genetic Algorithms especially things solved by Cellular Automata.
Strain’s Map:
- Programming Languages are Formal Languages
- Algorithms
- Computability: FSM, Automata, NP/P
- Neural Basis of Language and Thought
- Linear Algebra for Graphics.
- Relational Logic for Databases.
- AI: artificial intelligence science
- Cryptography
