[leetcode] 9. Palindrome Number _ Algorithm Problem Solve for python



1. Problem

9. Palindrome Number

Given an integer x, return true if x is a palindrome, and false otherwise.

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:

  • -2^31 <= x <= 2^31 - 1

2. Solution

I solved this problem like this.

  • It is so easy!
  • You change x to str.
  • confirm str(x) and str(x)[::-1] are equal.
class Solution:
    def isPalindrome(self, x: int) -> bool:
        return str(x) == str(x)[::-1]