009 回文数

public boolean isPalindrome(int x) {
    if (x < 0 || (x % 10 == 0) && x != 0) {
        return false;
    }
    int rev = 0;
    while (rev < x) {
        rev = rev * 10 + x % 10;
        x = x / 10;
    }
    return x == rev || x == rev / 10;
}