64_timers.yaml

- slug: 64_timers
  title: "Timers"
  difficulty: medium
  topics: ["time", "goroutines", "concurrency", "synchronization"]
  test_regex: ".*"
  hints:
    - "Use a map[string]*time.Timer to track active timers by key."
    - "Use a mutex to safely access the timers map concurrently."
    - "Start a timer with time.AfterFunc(d, fn) to run a callback after duration d."
    - "If Start is called again for an existing key, stop and replace the old timer."
    - "Stop should remove the timer from the map and prevent the callback from firing."
    - "Reset can call timer.Reset(d) to reschedule the same callback."
    - "Remember to remove timers from the map after they fire to avoid memory leaks."
    - "Write tests to verify Start, Stop, and Reset behavior, including concurrency scenarios."