数学方法
class Solution {
public boolean isPalindrome(int x) {
//边界判断if (x < 0) return false;int div = 1;//while (x / div >= 10) div *= 10;while (x > 0) {
int left = x / div;int right = x % 10;if (left != right) return false;x = (x % div) / 10;div /= 100;}return true;}
}