Flatten a tree with depth in Rust
Rust interview exercise on Structs & Enums, difficulty 3 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Write flatten_tree(nodes) that walks the tree depth-first and returns (name, depth) for every node, with roots at depth 0. The given node(..) helper only exists to make trees short to write.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.