Invert keys and values in Rust
Rust interview exercise on Structs & Enums, difficulty 1 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 invert(map) that swaps keys and values. When two keys share a value, the key that comes later alphabetically wins (that is the order a BTreeMap iterates in).
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.