class Solution {
public:
bool isPalindrome(int x) {
if(x < 0) return false;
long div = 1;
while(x >= 10 * div)
div *= 10;
while(x) {
int right = x % 10;
int left = x / div;
if(left != right) return false;
x = (x % div) / 10;
div = div / 100;
}
return true;
}
};