9. Palindrome Number

题意描述：Determine whether an integer is a palindrome（回文结构）. Do this without extra space.

思路：回文特点 数字翻转之后与原数字值相等

AC代码：

class Solution {
public:
bool isPalindrome(int x) {
if(x < 0)
return false;
int sum = 0;
int tar = x;
while((tar * 10 )/10){
sum *= 10;
sum += tar%10;
tar /= 10;
}
//cout << "sum = " << sum << endl;
return sum == x;
}
};