"""
Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Example 1:

Input: 121
Output: true
Example 2:

Input: -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
Example 3:

Input: 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
Follow up:

Coud you solve it without converting the integer to a string?
"""

class Solution:
    def isPalindrome(self, x: int) -> bool:
        orig = x
        back_x = 0
        while x > 0:
            back_x = (back_x * 10) + (x % 10)
            x = x // 10
        return orig == back_x
class Solution(object):
    def isPalindrome(self, x):
        """
        :type x: int
        :rtype: bool
        """
        if (x < 0) or (x % 10 == 0 and x != 0): return False
        rev = 0
        while x > rev:
            rev = rev * 10 + x % 10
            x //= 10
        return x == rev or x == rev // 10
