9. Palindrome Number

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

判断一个数是不是回文数

C++(182ms):

class Solution {
public:
    bool isPalindrome(int x) {
        if(x < 0 || (x != 0 && x%10 == 0))
            return false ;
        int sum = 0 ;
        while(x > sum){
            sum = sum*10 + x%10 ;
            x /= 10 ;
        }
        return (x == sum) || (x == sum/10) ;
    }
};

Java(188ms):

class Solution {
    public boolean isPalindrome(int x) {
        if(x < 0 || (x != 0 && x%10 == 0))
            return false ;
        int sum = 0 ;
        while(x > sum){
            sum = sum*10 + x%10 ;
            x /= 10 ;
        }
        return (x == sum) || (x == sum/10) ;
    }
}