Exam-Day Playbook — Recursion & Memo Notes for Interviews

Read this the night before a test, and again just before it starts.

The 10-minute method

Minute	Do this
0–1	Read what to return. List all? Count? Min/max? Yes/no?
1–3	Draw the tree for 2–3 items. What are the choices?
3–4	Write the promise as a comment: `// f(i, rem) = …`
4–5	Base cases, using the cheat sheet below
5–8	Code the plain recursion. Run the samples.
8–10	Add the memo (4 steps) if calls repeat. Submit.

Plain recursion that passes the small tests often earns partial marks. Don’t skip it.