9.回文数。一秒看懂

class Solution {
    public boolean isPalindrome(int x) {
        if(x < 0) return false;
        int copy_x = x, result = 0;
        while(copy_x != 0){
            result = result*10 + copy_x%10;
            copy_x = copy_x/10;
        }
        return x == result;
    }
}