[리트코드 / LeetCode] 9. Palindrome Number 풀이 - python3

문제 원문

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.
Follow up: Could you solve it without converting the integer to a string?
 
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

코드 원문

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

풀이

거꾸로 봐도 똑같은 숫자인지 판단하는 문제입니다.

음수는 -까지 문자로 인식해서 자연스래 양수만 True로 반환됩니다

간단하게 문자열을 뒤집는 함수를 작성하여 풀었습니다.

성공 코드

class Solution:
    def reverse(text):	//입력받은 문자열을 뒤집어서 반환
        result = ""
        for i in text :
            result = i + result

        return result

    def isPalindrome(self, x: int) -> bool:
        Num = str(x)
        ReverseNum = Solution.reverse(Num)

        return Num == ReverseNum

결과

Runtime: 72 ms, faster than 32.99% of Python3 online submissions for Palindrome Number.

Memory Usage: 14.2 MB, less than 70.28% of Python3 online submissions for Palindrome Number.