leetcode3

题目链接：https://leetcode-cn.com/problems/longest-palindromic-substring/

代码：

 1 class Solution(object):
 2     def longestPalindrome(self, s):
 3         """
 4         :type s: str
 5         :rtype: str
 6         """
 7         n = len(s)
 8 
 9         m,l,r = 0,0,0
10 
11         for i in range(n):
12             # odd case
13             for j in range(min(i+1,n-i)):
14                 if s[i-j] != s[i+j]:
15                     break
16                 if 2*j + 1 > m :
17                     m = 2 * j + 1
18                     l = i-j
19                     r = i+j
20 
21 
22             if i+1 < n and s[i] == s[i+1]:
23                 for j in range(min(i+1,n-i-1)):
24                     if s[i-j] != s[i+j+1]:
25                         break
26                     if 2 * j + 2 > m :
27                         m = 2*j +2
28                         l = i-j
29                         r = i+j+1
30         return s[l:r+1]

 

posted @ 2019-05-13 02:06  mingyu02  阅读(102)  评论(0)  编辑  收藏  举报