You have no idea why they didn't hire you. It's probably a completely different reason, even if they said it was the linked list question. If the interviewer

You have no idea why they didn't hire you. It's probably a completely different reason, even if they said it was the linked list question. If the interviewer likes a candidate, every minor error is forgiven. If the interviewer doesn't like the candidate, any minor mistake is a reason for "no hire". Just move on. There are plenty of opportunities.