문제

리트코드 5. Longest Palindrome Substring
난이도: ⭐⭐

Given a string s, return the longest palindromic substring in s.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.
(문자열 배열을 받아 애너그램 단위로 그루핑하라)

예시 1

Input: s = "babad"
Output: "bab"
Note: "aba" is also a valid answer.

예시 2

Input: s = "cbbd"
Output: "bb"

풀이 : 중앙을 중심으로 투 포인터 확장

class Solution:
    def longestPalindrome(self, s: str) -> str:
        
        def expand(left: int, right: int) -> str:
            while left >= 0 and right < len(s) and s[left] == s[right]:
                left -= 1
                right += 1
            return s[left+1 : right]
        
        if len(s) < 2 or s == s[::-1]:
            return s
        
        result = ''
        for i in range(len(s)-1):
            result = max(result, expand(i, i+1), expand(i, i+2), key=len)
            
        return result
        
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결과: 통과, 36ms