9. Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.

---

public class Solution {
    public boolean isPalindrome(int x) {
        
        if(x < 0)   return false;
        
        int div = 1;
        while(x / div >= 10){
            div *= 10;
        }
        
        while(x > 0){
            int l = x / div;
            int r = x % 10;
            if(l != r) return false;
            
            x = x % div; // rm left most digit
            x = x / 10;  // rm right modet digit
            div /= 100; // 10 for left, 10 for right
        }
        
        return true;
        
        
    }
}