Deduplicate account sign-ups by email and phone

A sign-up service processes account registrations one at a time, in the order they arrive. You get three lists of the same length n: names, emails and phones. Index i of each list describes account i.

Implement:

register_accounts(names: list[str], emails: list[str], phones: list[str]) -> list[bool]

Return a list where entry i is True if account i registers successfully and False if it is a duplicate.

Rules

• An account registers only if its email is not claimed by an earlier registered account and its phone is not claimed by an earlier registered account.
• A duplicate account claims nothing. Its email and phone do not block later accounts.
• names is part of the record but is never used to detect duplicates.
• Emails and phones are checked separately: an email only collides with emails, a phone only with phones.
• An empty string (or None) means the field was not given. It never collides.
• Raise ValueError if the three lists have different lengths.

Part 2: normalization

Real users type the same identifier in different ways. Before checking, normalize:

• emails: trim surrounding spaces and compare case-insensitively;
• phones: keep only the digits (so "+1 (415) 555-0100" equals "14155550100").

Example

Output: [True, True, False, False, True].

Constraints

• 0 <= n <= 10^5; each email and phone is at most 100 characters.
• Aim for O(n) time for typical string lengths. State the time and space complexity.

Reconstructed from the reported question; details may differ from what interviewers ask.