LeetCode 9. Palindrome Number

class Solution {
public:
    bool isPalindrome(int x) {
        if(x<0) return false;
        if(x<10) return true;
        int i=1,j=0,a[20]={0};
        while (x!=0){
            a[i]=x%10;
            x/=10;
            i++;
        }
        while(a[j]==a[i]&&j<=i){
            j++;i--;
        }
        if (j>=i) return true;
        else return false;
        
    }
};