Palindrome Number Check

MathNumber Theory

Given an integer, write a function to determine if it is a palindrome. An integer is a palindrome when it reads the same backward as forward. For example, 121 is a palindrome, but 123 is not.

Example 1

Input

[
  121
]

Output

true

Explanation. 121 reads as 121 backwards, which makes it a palindrome.

Example 2

Input

[
  -121
]

Output

false

Explanation. Negative numbers cannot be palindromes by definition.

Example 3

Input

[
  10
]

Output

false

Explanation. 10 reads as 01 backwards which is not the same.

Example 4

Input

[
  1221
]

Output

true

Explanation. 1221 reads as 1221 backwards, which makes it a palindrome.

Follow-up: Can you solve the problem in O(1) space complexity?

Constraints:

You must not convert the integer into a string to solve this problem. The input integer could be negative, but negative numbers cannot be palindromes.

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