leetcode -- Palindrome Number

https://leetcode.com/problems/palindrome-number/

understanding:

题目原意是要我们用数学的办法去coding，而不是转化成string。但转化成string也可以通过。

my code:

class Solution(object):
    def isPalindrome(self, x):
        """
        :type x: int
        :rtype: bool
        """
        if x >=0:
            x = str(x)
        else:
            return False
        i = 0
        j = len(x) - 1
        
        while j > i:
            
            if x[i] == x[j]:
                i += 1
                j -= 1
            else:
                break
        if j <= i:
            return True
        else:
            return False