How to study computer science: theory, algorithms and systems

What makes computer science hard

The subject is abstract and layered. Algorithms and complexity need mathematical reasoning, operating systems and networks need a mental model of what the machine is doing, and theory of computation is proof-heavy. Exams ask you to trace code by hand, explain why an algorithm works, and state its running time.

Students often watch a solution make sense and then cannot write it unaided. Understanding on a read-through is not the same as producing it.

Study methods that suit computer science

Alternate understanding, recall and practice.

• Trace algorithms by hand on small inputs until you can predict every step.
• Re-implement data structures and algorithms from a blank file without notes.
• Explain why an algorithm is correct and what its complexity is, in words.
• Spaced recall for definitions, complexity classes, protocols and trade-offs.
• Solve past exam questions under time with pen and paper if that is how you will be examined.

How to use Type to Study for computer science

Upload lecture notes exported as PDF, textbook chapters, or a topic such as hash tables. Flowcharts beside the lesson light up the steps of an algorithm or a protocol handshake. Typing the written explanation of an algorithm, its invariants and its complexity builds the vocabulary for written exams, and the recall pass tests the key terms. Flashcards and the final exam cover the theory.

It does not run code. Write and execute programs in an editor or IDE, and practise problems on a coding platform. See the programming page for learning to code, and the computer science students page.