Code RoomDeduplicate stream
MediumPrep Room Coding #797

Deduplicate stream

CodingDistributed systemsMid–Senior~25 min

A stream may deliver the same message more than once. Given a list of (msg_id, payload) tuples in arrival order, return the payloads of only the first occurrence of each msg_id, in arrival order, as a list. Subsequent duplicates of an already-seen id are dropped regardless of payload. The input may be empty.

Implement
dedup_stream(messages: list[tuple]) → list
Examples
in[[[1,"a"],[2,"b"],[1,"c"]]]out["a","b"]
What a strong answer looks like

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.

0:00 of about 25 min
InputExpectedGot
[[[1,"a"],[2,"b"],[1,"c"]]]["a","b"]not run yetsample