Ace the Rust Interview

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intermediate · order 69

Convert pointers to indices

list-index-01Related book chapters: 18, 21 (optional — this page is complete on its own)indices

Slug: list-index-01 · Paired reading: Chapters 18 and 21

Prompt

Given a singly linked list as Option<Box<Node>> with val / next, convert it into a flat arena: Vec<i32> values plus Vec<Option<usize>> next-links (same length). Return (values, nexts) with head at index 0 when non-empty. Empty input → two empty vecs.