Update palindrome_checker.py

palindrome_checker.py

@@ -1,7 +1,23 @@
-# palindrome_checker.py
+import re
+
 def is_palindrome(s):
-    return s == s[::-1]
+    # Normalize the string: remove non-alphanumeric characters and convert to lowercase
+    normalized_s = re.sub(r'[^A-Za-z0-9]', '', s).lower()
+
+    # Early exit for trivial cases
+    if len(normalized_s) <= 1:
+        return True
+
+    # Check for palindrome
+    left, right = 0, len(normalized_s) - 1
+    while left < right:
+        if normalized_s[left] != normalized_s[right]:
+            return False
+        left += 1
+        right -= 1
+
+    return True
 
 if __name__ == "__main__":
-    word = input("Enter a word: ")
+    word = input("Enter a word or phrase: ")
     print(f"{word} is a palindrome: {is_palindrome(word)}")