snippets

public boolean isPalindrome(String s) {
    int i = 0, j = s.length() - 1;
    while (i < j) {
        while (i < j && !Character.isLetterOrDigit(s.charAt(i))) i++;
        while (i < j && !Character.isLetterOrDigit(s.charAt(j))) j--;
        if (Character.toLowerCase(s.charAt(i)) != Character.toLowerCase(s.charAt(j))) {
            return false;
        }
        i++; j--;
    }
    return true;
}