最长回文子串（LeetCode）

题目

给你一个字符串 ，找到  中最长的回文子串

解题

def expand_around_center(s, left, right):while left >= 0 and right < len(s) and s[left] == s[right]:left -= 1right += 1return s[left + 1:right]def longest_palindrome(s):if len(s) < 2:return slongest = ""for i in range(len(s)):# 奇数长度回文odd_palindrome = expand_around_center(s, i, i)if len(odd_palindrome) > len(longest):longest = odd_palindrome# 偶数长度回文even_palindrome = expand_around_center(s, i, i + 1)if len(even_palindrome) > len(longest):longest = even_palindromereturn longest# 测试例子
s = "babad"
print("最长回文子串：", longest_palindrome(s))

最长回文子串： bab