9. Palindrome Number

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

 

 

PS：判断一个整数是否是回文，只需要取后一半的数与前一半的数字相比。 

 

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