class Solution {
public:
bool isPalindrome(int x) {

//negative number
if(x < 0)
return false;

int len = 1;
while(x / len >= 10)
len *= 10;

while(x > 0) {

//get the head and tail number
int left = x / len;
int right = x % 10;

if(left != right)
return false;
else {
//remove the head and tail number
x = (x % len) / 10;
len /= 100;
}
}

return true;
}
};

leetcde 9 Palindrome Number