leecode 5. Longest Palindromic Substring最长回文子串

leecode 5. Longest Palindromic Substring最长回文子串

Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000.

Example 1:

Input: “babad”
Output: “bab”
Note: “aba” is also a valid answer.
Example 2:

Input: “cbbd”
Output: “bb”

class Solution:
    def longestPalindrome(self, s: str) -> str:
        r=''
        for i,j in [(i,j) for i in range(len(s)) for j in (0,1)]:
            while i>-1 and i+j<len(s) and s[i]==s[i+j]:
                i,j=i-1,j+2
            r=max(r,s[i+1:i+j],key=len)
        return '' if not s else r