Python interview question: valid palindrome

EasyTwo pointers

For anniversary “mirror” promo codes, return True if code reads the same in both directions, ignoring case and every character that isn’t a letter or a digit. Letters aren’t only A–Z: ñ and é count too. An empty code counts as a mirror.

def is_mirror_code(code: str) -> bool:

Example

• code = 'Rotor-7-rotor' → Truehyphens are skipped, and R matches r
• code = 'Kayak 2026 kayak' → False2026 reversed is 6202

Skills it tests

• Character normalization

More interview questions

• Python: Range sum queriesEasy · Prefix sums
• Python: Two sum in a sorted arrayEasy · Two pointers
• Python: Longest subarray with at most k distinct valuesMedium · Sliding window
• Python: Merge two sorted linked listsEasy · Linked list
• Python: Maximum average subarray of at least kHard · Binary search

All questions