Palindrome Permutation Function | Dataford Interview Questions

A text-processing component in the Cox Communications app needs to determine whether a user-entered phrase can be rearranged into a palindrome. Implement a function that performs this check without generating the possible permutations.

A string is a palindrome permutation if its characters can be reordered to read the same forward and backward. Treat uppercase and lowercase letters as equal, and ignore spaces and non-alphanumeric characters.

Formal Specification

Given a string s, return True if its normalized characters can be rearranged into a palindrome. Return False otherwise. The input and output types are str and bool.

A normalized string can form a palindrome when at most one character has an odd frequency. This is because every other character must occupy matching positions on opposite sides of the palindrome.

Constraints

0 <= len(s) <= 10^5
s contains ASCII letters, digits, spaces, and punctuation
Matching is case-insensitive
Spaces and non-alphanumeric characters are ignored

Function Signature

def is_palindrome_permutation(s):

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