索引 思路1:分治策略 思路2:Brute Force - O(n^3) 思路3:动态规划? O(n^2)版,错解之一:420 ms O(n^2)版,错解之二:388 ms O(n)版,思路转变: 100 ms 细节上的优化(JavaScript限定) 问题描述:https://leetcode.com/problems/longest-substring-without-repeating-characters/ 思路1:分治策略 感觉两下半写完了..没啥收获,就别出心载先写了个分治版本,结果…

https://leetcode.com/problems/longest-substring-without-repeating-characters/ public class Solution { public int lengthOfLongestSubstring(String s) { if(s.length() == 0 )return 0; HashMap<Character,Integer> map = new HashMap<Character, Integer>…

3. Longest Substring Repeating Character Difficulty:Medium The link: https://leetcode.com/problems/longest-substring-without-repeating-characters/ Description : Given a string, find the length of the longest substring without repeating character. Exa…

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…

[题目]: Write a program to find the node at which the intersection of two singly linked lists begins. For example, the following two linked lists: A: a1 → a2 ↘   c1 → c2 → c3      ↗ B: b1 → b2 → b3 begin to intersect at node c1. Notes: 1. If the two li…

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…

目录 为什么要刷LeetCode 刷LeetCode有哪些好处? LeetCode vs 传统的 OJ LeetCode刷题时的心态建设 C#如何刷遍LeetCode 选项1: VS本地Debug + 在线验证后提交 选项2: VS Code本地Debug + 在 LeetCode 插件中验证和提交 为什么要刷LeetCode 大家都知道,很多对算法要求高一点的软件公司,比如美国的FLAGM (Facebook.LinkedIn.Amazon/Apple.Google.Microsoft),或国…

最近搞了几场编程比赛,面试题或者是LeetCode周赛.每次都不能做完,发现时间不够用. 看了别人的代码才知道,同样实现相同的功能,可能别人只需要用一个恰当的函数,就会比自己少些不少代码,争得了时间.所以这些小技巧对于提升名次来说,十分重要.以后需要 更加重视才行. 拿LeetCode Weekly Contest 27 来举个例子: 第二题: 556. Next Greater Element III Given a positive 32-bit integer n, you need to…

想要学习算法.应付笔试或者应付面试手撕算法题,相信大部分人都会去刷 Leetcode,有读者问?如果我在 leetcode 坚持刷它个 500 道题,以后笔试/面试稳吗? 这里我说下我的个人看法,我认为不稳.下面说说为啥不稳以及算法题应该如何刷.如何学才比较好,当然,也会推荐自己学过的资料. 一.先说说笔试题 在刷 leetcode 的时候,你会发现,每道题的题意都很短,你只需要花十几秒的时间,就知道这道题是要你干嘛了,并且每道题所用道的算法思想都很明确,动态规划.递归.二分查找等,你可能很快就…

关于螺旋矩阵 这是我曾经遇到过的面试题,在 LeetCode 上找到了题目的原型,难度中等.题目描述如下: 给定一个包含 m x n 个元素的矩阵(m 行, n 列),请按照顺时针螺旋顺序,返回矩阵中的所有元素. 示例 1: 输入: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] 输出: [1,2,3,6,9,8,7,4,5] 示例 2: 输入: [ [1, 2, 3, 4], [5, 6, 7, 8], [9,10,11,12] ] 输出: [1,2,3,4…