Question
Implement RFC 6238 TOTP. Given a base32-encoded shared secret, a Unix timestamp (seconds), a time step in seconds (e.g. 30), and the number of output digits, return the TOTP code as a zero-padded string. Compute the counter as floor(timestamp / step), pack it as an 8-byte big-endian value, HMAC-SHA1 it with the decoded secret, apply the standard dynamic truncation (offset = last nibble of the digest; take 4 bytes starting there, mask the top bit), then take modulo 10**digits and left-pad with zeros to 'digits' length.
totp(secret_b32: str, timestamp: int, step: int, digits: int) → str["GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ",59,30,6]out"287082"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.