[LeetCode] Palindrome Number

public class Solution {
    public boolean isPalindrome(int x) {
        
        if (x<0) return false;
        
        int highNum = 1;
        int lowNum  = 1;
        
        while (x/highNum >= 10 ) highNum *= 10;
        while (highNum > lowNum) {
            if ((x/highNum)%10 != (x/lowNum)%10) return false;
            highNum /= 10;
            lowNum *= 10;
        }
        
        return true;
        
    }
}