Each packet is an original, offline TypeScript repository exercise. Start AI-free, run deterministic tests, then compare with the compact instructor solution. Optional AI use is a separate, explicitly recorded practice condition.
Repair a FIFO queue
Replace the empty-dequeue defect and repeated front removal with a FIFO implementation that releases references and documents amortized compaction.
Single-threaded and in-memory; no distributed queue or concurrency framework.Open packetExtend a prefix catalog
Preserve exact lookup and add unique ASCII prefix results in lexicographic order under a validated limit.
No fuzzy search, Unicode normalization, remote index, or search service.Open packetRepair dependency planning
Normalize duplicate edges, include isolated tasks, detect disconnected cycles, and preserve deterministic output.
Planning only; no task execution, scheduling service, or parallel worker system.Open packetAdd TTL to a bounded LRU
Use an injected monotonic clock, exact expiry boundary, purge-before-evict behavior, zero-TTL removal, and live-entry LRU eviction.
Single-threaded; no timers, persistence, real waits, or production-cache claim. Put may take O(capacity).Open packetReach this point to mark the lesson as read.