Implement a Durable Key-Value Store with File Segmentation

Problem: Implement a Durable Key-Value Store with File Segmentation Implement a durable key-value store that persists data to disk and can reload it after a process restart. Support the following operations: SET key value: Insert or overwrite a key-value pair. GET key: Return the value for a key; print NOT_FOUND if the key does not exist. DEL key: Delete a key. Deleting a missing key produces no output. REOPEN: Simulate closing and reopening the store. All successfully persisted data must remain readable afterward. Persistence requirements Data must be written to the supplied storage directory, not kept only in memory. An initial version may store all data in one file. Follow-up: no data file may exceed 1024 bytes. As data grows, automatically split it across multiple files. Keys and values are UTF-8 strings. Each encoded key-value record is at most 1024 bytes. After repeated SETs for the same key, a reload must return the newest value. After DEL, the key must remain absent after a reload. Input format Line 1: storage directory path store_dir Line 2: number of operations Q Next Q lines: one command, formatted as SET key value, GET key, DEL key, or REOPEN. value contains no newline but may contain spaces. In a SET command, everything after the first space following key is the value. Output format For every GET, print one line containing its value or NOT_FOUND. Constraints 1 <= Q <= 10^4 The UTF-8 encoded length of each key and value is at most 512 bytes. Every data file must be at most 1024 bytes. Example Input /tmp/kv_case1 5 SET name alice GET name REOPEN GET name GET missing Output alice alice NOT_FOUND