Made it to the third part (CIDR blocks) but the output was wrong and I didn't catch why until after the call ended.
Start by clarifying requirements: IPv4 vs IPv6, strictness of validation, and expected output for CIDR. Then outline a modular design: a parser for base IP addresses and a separate CIDR handler that computes network and broadcast addresses. Implement with clear error handling and discuss trade-offs like regex vs manual parsing.
Pro tip: Mention that you would write comprehensive unit tests covering edge cases like leading zeros, out-of-range octets, and CIDR prefixes at boundaries (0 and 32 for IPv4). This shows attention to detail and production readiness.
Ask about supported IP versions, validation strictness, and expected output format for CIDR (e.g., network address, broadcast, or just validation).
Decide between regex and manual parsing. For IPv4, split by dots and validate each octet; for IPv6, handle groups and compression. For CIDR, split on '/' and validate prefix length.
Write functions to parse and validate IP addresses, then extend to CIDR by computing network and broadcast addresses using bitwise operations.
Cover invalid inputs, leading zeros, IPv4-mapped IPv6, and CIDR prefixes at boundaries. Ensure proper error messages.
Compare regex vs manual parsing for performance and readability. Outline a testing strategy with unit tests for all edge cases.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.