LeetCode-longest-palindromic-substring

题目描述

Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring.

# Leetcode# 3. Longest Substring Without Repeating Characters# https://leetcode.com/problems/longest-substring-without-repeating-characters/description/# 无重复最长子串的长度# 思路：通过set来保存无重复的字符，start记录子串开始位置，end记录结束位置；# 遍历字符串，如果set中不存在当前字符，则加入，同时end+1，更新maxLength# 如果存在，就移除set中，和当前字符相同的字符，在s位置之前的所有字符# 如khabcabc，找到和第二个a相同的a，位于index=2，之前的依次是kha，移除set中的k\h\a.重新计数。class Solution(object):    def lengthOfLongestSubstring(self, s):        """        :type s: str        :rtype: int        """        n = len(s)        myset = set()        start = end = maxLength = 0        while start < n and end < n:            if not myset.__contains__(s[end]):                myset.add(s[end])                end += 1                maxLength = max(maxLength, end - start)            else:                myset.remove(s[start])                start += 1        return maxLength