Implement an In-Memory Key-Value Store with Write-Ahead Logging for Crash Recovery

Problem: Implement an In-Memory Key-Value Store with Write-Ahead Logging for Crash Recovery Implement an in-memory key-value store that can recover its state after a crash by replaying an on-disk log file. Requirements Basic operations: PUT(key, value) overwrite or create GET(key) return value or None if missing DELETE(key) remove a key (optional but recommended) Persistence and recovery: Every write operation must be appended to a log file (WAL / append-only log). On restart, rebuild the in-memory state by replaying the log. You must define and implement The log record format (e.g., text lines like PUT\tkey\tvalue / DEL\tkey, or binary) Replay ordering and overwrite semantics How to handle special characters (tabs/newlines) inside keys/values (you may define an encoding) Constraints Up to 1e5 operations Key/value length up to 1e4 If a log entry is persisted, the system should recover to the correct state after a crash Sample Tests First run: PUT(a,1) PUT(b,2) PUT(a,3) GET(a) -> 3 After crash and restart: Replay log GET(a) -> 3, GET(b) -> 2 Delete: DELETE(b) Restart then GET(b) -> None Restart with empty log: GET(x) -> None After many writes, restart: Recovery should be acceptable (linear replay). Example Input log: (empty) ops: GET a Output None