Palindrom-Labor • Hands-On Lab

Live-Prüfung Two-Pointer O(1)

Ergebnis:

✓ ECHTES PALINDROM

O(1) Auxiliary Space

Code-Gegenüberstellung Audit

Naiver 1st-Shot (O(N) RAM, löscht Umlaute)

import re

def is_palindrome(s: str) -> bool:
-   clean = re.sub(r'[^a-zA-Z0-9]', '', s).lower() # Löscht ä, ö, ü!
-   return clean == clean[::-1]                    # Verdoppelt RAM (O(N))

In-Place Two-Pointer (O(1) RAM, Unicode)

def is_palindrome(s: str) -> bool:
    left, right = 0, len(s) - 1
    while left < right:
        while left < right and not s[left].isalnum(): left += 1
        while left < right and not s[right].isalnum(): right -= 1
        if s[left].casefold() != s[right].casefold():
            return False
        left += 1; right -= 1
    return True

14/14 Pytests PASSED pytest test_palindrom.py -v

Test	Input	Erwartung	Status
test_empty_string	""	True	PASSED
test_german_umlaute	"Na, Freibierfan?"	True	PASSED
test_panama_sentence	"A man, a plan, a canal, Panama"	True	PASSED
test_non_palindrome	"Not a palindrome"	False	PASSED

Palindrom-Labor: O(1) vs. O(N)