Palindrome String

Problème

Decide whether text is a palindrome, considering only letters and digits and ignoring case.

Implement is_palindrome(text).

text: The text to check (ASCII characters).

Return true for a palindrome, otherwise false.

0 ≤ length ≤ 10,000

Exemple 1

Entrée :
text = "Racecar"

Sortie attendue :
expected = True

Entrée :
std::string text = "Racecar";

Sortie attendue :
bool expected = true;

Entrée :
string text = "Racecar";

Sortie attendue :
bool expected = true;

Lowercased, "racecar" reads the same both ways.

Exemple 2

Entrée :
text = "hello"

Sortie attendue :
expected = False

Entrée :
std::string text = "hello";

Sortie attendue :
bool expected = false;

Entrée :
string text = "hello";

Sortie attendue :
bool expected = false;

"hello" backwards is "olleh", which is different.

Essayez d'abord seul, puis ouvrez les indices un par un.

Indice 1

Ignore anything that is not a letter or digit before comparing.

Indice 2

Move inward from both ends, comparing case-insensitive characters.

Indice 3

Skip punctuation and spaces carefully so they do not break valid palindromes.

Complexité attendue

O(n) time, O(1) extra space

Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.