Palindrome Number

/*
LeetCode 9:
Determine whether an integer is a palindrome. Do this without extra space.


Solution:
Language: C++
Tag: reverse
hint: exclude negatives
*/

class Solution {
public:
    bool isPalindrome(int x) {
        if (x < 0) {
            return false;
        }
        // 1. O(1) space + O(log10(n)) time
        int m = 0, tmp = x;
        while (tmp != 0) {
            m = m * 10 + tmp % 10;
            tmp /= 10;
        }
        return (m == x);
    }
};