Question
A write-ahead log records mutations to a key-value store. You are given an ordered list of log entries, each either ["put", key, value] or ["del", key]. Compaction replays the log to compute the final materialized state, where each key's value is whatever the last put for it set (a later del removes the key entirely; a put after a del re-adds it). Return the compacted state as a list of [key, value] pairs sorted by key ascending. Keys are strings; values are integers.
wal_compact(entries: list[list]) → list[list][[["put","a",1],["put","b",2],["put","a",3],["del","b"]]]out[["a",3]]State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.