Status: IN
Design decisions — no input validation, in-place mutation of arguments, per-directory duplication of data structures — collectively optimize solutions for single-run correctness on LeetCode's online judge rather than for reuse, composability, or library consumption.
each decision is rational for a judge environment (trusted input, single caller, no shared state) but would be a defect in reusable library code
Depends on (SL): no-validation-is-deliberate-contract, in-place-mutation-with-return-convention, duplication-over-shared-infrastructure