**Approach**: Normalize (lowercase, alphanumeric only) and compare with reverse. **Code**: `def is_palindrome(s): cleaned = "".join(c.lower() for c in s if c.isalnum()); return cleaned == cleaned[::-1]`. **Two-pointer** (O(1) space, early exit): `lo, hi = 0, len(s)-1; while lo <...
Red Flag: Forgetting to handle non-alphanumeric or case. Pro-Move: 'I ask about edge cases first: empty string, unicode, case. I implement two-pointer for O(1) space and mention when string concat would be simpler.'
This medium-level Python/Coding question appears frequently in data engineering interviews at companies like Altimetrik, Infosys. While less common, it tests deeper understanding that distinguishes strong candidates. Mastering the underlying concepts (join, python) will help you answer variations of this question confidently.
Break this problem into components. Identify the core trade-offs involved, then walk the interviewer through your reasoning step by step. Demonstrate awareness of edge cases and production considerations - this is what separates good answers from great ones.
Approach: Normalize (lowercase, alphanumeric only) and compare with reverse. Code: def is_palindrome(s): cleaned = "".join(c.lower() for c in s if c.isalnum()); return cleaned == cleaned[::-1]. Two-pointer (O(1) space, early exit): lo, hi = 0, len(s)-1; while lo < hi: ... if not s[lo].isalnum(): lo+=1; continue; ... if s[lo].lower() != s[hi].lower(): return False; lo, hi = lo+1, hi-1; return True. Clarify: Case sensitivity? Non-alphanumeric? Empty string (usually True). Scalability: Two-pointer avoids allocating a new string for very long inputs.
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Analyze My Answer — FreeAccording to DataEngPrep.tech, this is one of the most frequently asked Python/Coding interview questions, reported at 2 companies. DataEngPrep.tech maintains a curated database of 1,863+ real data engineering interview questions across 7 categories, verified by industry professionals.