9. Palindrome Number (Math)

링크 - https://leetcode.com/problems/palindrome-number/description/?envType=company&envId=facebook&favoriteSlug=facebook-thirty-days

난이도 - Easy

Intuition

수를 10으로 나누면서 풀면 되는 쉬운 문제이다.

Code

class Solution:
    def isPalindrome(self, x: int) -> bool:
        if x < 0 or (x%10 == 0 and x != 0):
            return False

        reversed_x = 0
        while x > reversed_x:
            reversed_x = reversed_x*10 + x%10
            x //= 10

        return x == reversed_x or x == reversed_x // 10

Complexity

Time Complexity: O(log10(N))

Space Complexity: O(1)