문제 링크

1️⃣ 내 풀이

class Solution:
    def longestPalindrome(self, s: str) -> str:
        if len(s)<=1 or s == s[::-1]:
            return s

        def expand(left, right):
            res = ''
            for i in range(0, len(s)-1):
                start = i+left
                end = i + right
                while start>=0 and end<len(s) and s[start] == s[end]:
                    res = max(res, s[start: end+1], key=len)
                    start-=1
                    end+=1
                res = max(res, s[start+1: end], key=len)
            
            return res
                
        return max('', expand(0,0), expand(0,1), key=len)