Palindrome Algorithm on Whiteboard | Dataford Interview Questions

Sandia National Laboratories systems such as Astra may process human-readable labels containing spaces, punctuation, and mixed capitalization. Write an algorithm that determines whether a string is a palindrome after normalization.

A normalized string is read from left to right after removing every character that is not an ASCII letter or digit and treating uppercase and lowercase letters as equivalent. Return True if the normalized string reads identically forward and backward; otherwise, return False.

Formal Specification

Implement is_palindrome(s), where s is a string of ASCII characters. Return a Boolean value. An empty normalized string is considered a palindrome.

Constraints

0 <= len(s) <= 10^5
s contains only ASCII letters, digits, spaces, and punctuation
Comparisons are case-insensitive
Non-alphanumeric characters are ignored
An empty normalized string is considered a palindrome

Function Signature

def is_palindrome(s):

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