class Solution {
public:
bool isPalindrome(int x) {
if (x < 0 || x % 10 == 0 && x != 0) return false;
int reverse = 0;
while (x > reverse) { //到x<=reverse为止
reverse = reverse * 10 + x % 10;
x /= 10;
}
//第一种情况,原数为偶数位;第二种,原数为奇数位,while退出时会有reverse = x
return (x == reverse || x == reverse / 10);
}
};
class Solution:
def isPalindrome(self, x: int) -> bool:
if x < 0:
return False
return x == int(str(x)[::-1])