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Code RoomRegex validation gaps
MediumPrep Room Coding #4326

Regex validation gaps

Vibe & agenticAlgorithms & data structuresMid–Senior~14 min

A teammate found this regex in a log-parsing pipeline and asked an AI to explain it. The agent says: "It validates that a string is a well-formed IPv4 address, rejecting anything out of the 0–255 range per octet." You're about to rely on it to filter untrusted input. How do you confirm the explanation, and what's likely to be off?

Implement
is_canonical_ipv4(candidate: str) → bool
Examples
in["1.2.3.4"]outtrue
in["999.999.999.999"]outfalse
in["010.0.0.1"]outfalse
What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it (tests, edge cases, reading critically), and how you’d re-prompt or decompose to get it right.

0:00 of about 14 min

Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.