C++解法一: class Solution { public: int lengthOfLongestSubstring(string s) { ] = {},left = , res = ; ; index < s.size(); ++index) { || m[s[index]] < left) { res = max(res,index-left+); }else{ left = m[s[index]]; } m[s[index]] = index+; } return res; }…

LeetCode 3_Longest Substring Without Repeating Characters 题目描写叙述: Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc&quo…

3-Longest Substring Without Repeating Characters @LeetCode 题目 题目中得到的信息有: 一段字符串找出不重复子串的最大长度,只需要长度信息. 思路 肯定是需要将字符串遍历一遍,在遍历过程中就需要查找前面字符串是否出现该字符,因此这是该算法的重点.若没找到,长度加一,若找到了,长度会从前面该字符位置+1处开始算起.下面以图来说明: 假如我们以begin为子串的开始,current表示当前处理的位置.1)当前位置的字符没有出现在[begin,…

题目: Given a . For . 解题思路: 这个题让找一个字符串中具有不重复单词的最长子串的长度,如:ababc,子串为abc,长度为3.有这么几个方法: 方法一: 依赖字符串本身的一些特有函数,进行相应操作来完成.我们可以维护一个子串,来保存最长的无重复的子串,并记录当前子串的长度,如果遇到重复的字符,则去掉子串中重复的字符,一次进行下去,最终就能找到最长无重复子串.如str = ababc, substr = a, ab, ba, ab, abc....类似这样的思路.如下代码: /…

题目: Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest s…

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest subst…

原题链接: http://oj.leetcode.com/problems/longest-substring-without-repeating-characters/ 这道题用的方法是在LeetCode中很常用的方法,对于字符串的题目非常有用. 首先brute force的时间复杂度是O(n^3), 对每个substring都看看是不是有重复的字符,找出其中最长的,复杂度非常高.优化一些的思路是稍微动态规划一下,每次定一个起点,然后从起点走到有重复字符位置,过程用一个HashSet维护当前字…

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest subst…

July 16, 2015 Problem statement: Longest Substring Without Repeating Characters Read the blog: http://blog.csdn.net/fightforyourdream/article/details/17860983 这算法写了很多次, 时间太长, 半年前, 有一次写了二个小时, 写不下去, 想法不好, 没有办法收场; 接着, 又写了四天, 每天二小时, 把上次代码拿出来看, 有什么问题, 改写.…

题目来源:https://leetcode.com/problems/longest-substring-without-repeating-characters/ Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb"…