9. Palindrome Number

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

          

class Solution {
public:
    bool isPalindrome(int x) {
        if(x < 0)
        return false;
        int y = 0;
        int X = x;
        while(X){
            y = y*10 + X%10;
            X /= 10;
        }
        if (x==y)
        return true;
        else 
        return false;
        
    }
};

                                                 Brilliant solution!

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 = x/10;
        }
        return (x==sum)||(x==sum/10);
    }
};