Ace the Rust Interview

Enter your book access code

The curriculum, drills, tutor, and interviewer mode are for readers of Ace the Rust Interview. The code is printed in the Preface (Companion site access).

Don’t have the book yet? The landing page stays open — purchase unlocks this gym.

intermediate · order 147

Memoization vs the borrow checker

dp-memo-01Related book chapters: 22 (optional — this page is complete on its own)memoborrow

Slug: dp-memo-01 · Paired reading: Chapter 22

Prompt

Implement fn fib_memo(n: u32) -> u64 with a HashMap cache passed as &mut. The classic trap is holding a reference from get across a recursive call that needs insert — structure the code so it compiles without RefCell.