Validate palindrome with constraints
Company: Samsung
Role: Machine Learning Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Technical Screen
Given a string s, return true if s reads the same forward and backward after removing all non-alphanumeric characters and ignoring letter case. Implement an O
(n)-time, O(
1)-extra-space solution using two pointers. Follow-ups:
(a) Modify your solution to return true if s can become a palindrome after deleting at most one character;
(b) Discuss how you would support full Unicode (e.g., combining marks and non-ASCII letters);
(c) Provide test cases and analyze complexity.
Quick Answer: This question evaluates a candidate's ability to implement string-processing algorithms and two-pointer techniques under O(n) time and O(1) extra space constraints, including character filtering, case normalization, edge-case handling, and algorithmic complexity analysis.