leetcode 9. Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.

bool isPalindrome(int x) {
	long long int xx = x;
	if (xx < 0)
		return false;
	if (xx<10)
		return true;
	int k = 0;
	while (xx>0)
	{
		k++;
		xx /= 10;
	}
	xx = x;
	for (int i = 0; i<k / 2; i++)
	{
		int r1 = xx % 10;
		int r2 = xx / pow(10, k - 1 - 2 * i);
		if (r1 != r2)
			return false;
		xx -= (r1 + r2*pow(10, k - 1 - 2 * i));
		xx /= 10;
	}
	return true;
}

accepted