[Solved] Given an integer x, return true if x is palindrome integer. An integer is a palindrome when it reads the same backward as forward.

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Question

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 a palindrome while 123 is not.

Example 1:

Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.

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.

Constraints:

  • -231 <= x <= 231 - 1

Follow up: Could you solve it without converting the integer to a string?

Python Solution

class Solution:
    def isPalindrome(self, x: int) -> bool:        
        def reverse(n):
            rev=0
            while n!=0:
                rem = n%10
                rev=rev*10+rem
                n=n//10
            return rev

        if x<0:
            return False
        else:
            return x==reverse(x)
        

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