java回文算法

public static boolean isPalindrome(String str) {
    return str.equals(
       new StringBuilder(str)
       .reverse()
       .toString()
    );
}

public static boolean isPalindrome(String str) {
    int n = str.length();
    for (int i = 0; i < n; ++i) {
        if (str.charAt(i) != str.charAt(n-i-1)) return false;
    }
    return true;
}