Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000.
Example:
Input: "babad" Output: "bab" Note: "aba" is also a valid answer.
Example:
Input: "cbbd" Output: "bb"
题意：求最长回文串。
思路：我是从discuss区看到的，整体思路事从用两个指针j,k从内往外遍历，当遇到不能使回文成立的条件时，更新最大值记录
1 class Solution(object): 2 def longestPalindrome(self, s): 3 """ 4 :type s: str 5 :rtype: str 6 """ 7 if len(s)==0: return ‘‘ 8 if len(s)==1: return s 9 front = 0 10 l = 0 11 for i in range(len(s)): 12 if len(s)-i<l/2: break #当后面的字符串已经不能更新最大值时 13 j = k = i 14 while k+1<len(s) and s[k] == s[k+1]: k += 1 #跳过一样的字符 15 while j>0 and k+1<len(s) and s[j-1] == s[k+1]: #从里往外遍历 16 j -= 1 17 k += 1 18 if k-j+1 > l: 19 front = j 20 l = k-j+1 21 return s[front:front+l]
【LeetCode】5. Longest Palindromic Substring
原文：http://www.cnblogs.com/fcyworld/p/6285938.html