9. Palindrome Number

9. Palindrome Number

Given an integer x, return true if x is palindrome integer.

An integer is a palindrome when it reads the same backward as forward. For example, 121 is palindrome while 123 is not.

 

Example 1:

Input: x = 121
Output: true

Example 2:

Input: x = -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: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

Example 4:

Input: x = -101
Output: false

 

Constraints:

  • -231 <= x <= 231 - 1
python

class Solution:

    def isPalindrome(self, x: int) -> bool:

        if x < 0:

            return False

        origin = x

        revert_value=0

        

        while origin:

            revert_value = revert_value * 10 + origin%10

            origin = origin//10

            

        if(revert_value> pow(2,31)):

            return False

        

        if(x == revert_value):

            return True

        else:

            return False

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