LeetCode: Palindrome Number

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

   bool isPalindrome(int x) {  
     int d = 0;  
     int n = x;  
     if(x<0)return false;  
     while(n)  
     {  
       d++;  
       n=n/10;  
     }  
     int i = d-1, j = 0;  
     while(i>j)  
     {  
       int pi = pow(10,i), pj = pow(10,j), pk = pow(10,j+1);  
       if(x/pi != (x%pk)/pj)return false;  
       x = x%pi;  
       i--;j++;  
     }  
     return true;  
   }