longest专题

leetcode#32. Longest Valid Parentheses

题目 Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. For "(()", the longest valid parentheses substring is "()", wh

java常用算法之最长回文子串(Longest Palindromic Substring)

方法一：时间复杂度为O(n^3) public static String longestPalindrome1(String s) {int maxPalinLength = 0;String longestPalindrome = null;int length = s.length();// check all possible sub stringsfor (int i = 0; i

[LeetCode] 300. Longest Increasing Subsequence

题：https://leetcode.com/problems/longest-increasing-subsequence/description/ 题目 Given an unsorted array of integers, find the length of longest increasing subsequence. Example: Input: [10,9,2,5,3,7

[LeetCode] 409. Longest Palindrome

题：https://leetcode.com/problems/longest-palindrome/description/ 题目 Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with

[LeetCode] 128. Longest Consecutive Sequence

题：https://leetcode.com/problems/longest-consecutive-sequence/description/ 题目 Given an unsorted array of integers, find the length of the longest consecutive elements sequence. Your algorithm should

[LeetCode] 594. Longest Harmonious Subsequence

题：https://leetcode.com/problems/longest-harmonious-subsequence/description/ 题目 We define a harmonious array is an array where the difference between its maximum value and its minimum value is exactl

[LeetCode] 687. Longest Univalue Path

题：https://leetcode.com/problems/longest-univalue-path/description/ 题目 Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may no

[LeetCode] 524. Longest Word in Dictionary through Deleting

题：https://leetcode.com/problems/longest-word-in-dictionary-through-deleting/ 题目大意对s删除某些元素，使得删除后的s 为 d中的某个元素。思路 trie 首先将建立tire，然后是用dfs搜索，遍历s。 boolean dfs(TrieNode node,String s,StringBuilder cu

LeetCode - 32. Longest Valid Parentheses

32. Longest Valid Parentheses Problem's Link ---------------------------------------------------------------------------- Mean: 给定一个由'('和')'组成的字符串，求最长连续匹配子串长度. analyse: 定义一个stack<pair

【HDU】1595 find the longest of the shortest 枚举+最短路

传送门：【HDU】1595 find the longest of the shortest 题目分析：首先求出一条最短路，记录下最短路上用到的边，枚举删除每一条边，求一次最短路，求完后恢复删除的边。重复这一过程直到枚举完所有的边为止。所有删除边后求得的最短路里最长的那条就是答案。代码如下： #include <cstdio>#include <cstring>

USACO Section 2.3 Longest Prefix

题意：给你一大堆小字符串和一个大字符串求使用小字符串能拼出的大字符串的前缀最长是多少思路：由于数据不大所以可以尝试扫描大字符串每到一个位置用小字符串拼一下看看能拼多长拼的最远距离就是答案我用trie树来存小字符串集合扫描大字符串时如果该位置是可以向后延伸的（即之前能拼到这个位置）那么我用一个标记在trie树上爬每次发现一个小字符串结

Longest Substring with At Most K Distinct Characters

Given a string, find the length of the longest substring T that contains at mostk distinct characters. For example,Given s = “eceba” and k = 2, T is "ece" which its length is 3. 思路：跟 Longest Sub

Longest Substring with At Most Two Distinct Characters

Given a string, find the length of the longest substring T that contains at most 2 distinct characters. For example,Given s = “eceba”, T is "ece" which its length is 3. 思路：同向双指针，跟Longest Substrin

leetcode --- Longest Common Prefix

最长公共前缀(Longest Common Prefix) 题目：Write a function to find the longest common prefix string amongst an array of strings. 题目链接：https://leetcode.com/problems/longest-common-pref

uva10285 Longest Run on a Snowboard（dp之记忆化搜索）

10285 Longest Run on a Snowboard Michael likes snowboarding. That’s not very surprising, since snowboarding is really great. The bad thing is that in order to gain speed, the area must slide downwar

LeetCode #3. Longest Substring Without Repeating Characters

题意：计算一个字符串的中的最长的不含有重复字母的长度解法：尺取法的裸题了，维护2个指针l,r, 不断移动r指针，同时检查[l,r]是不是存在重复的了，如果存在就移动l指针了 class Solution {public:int lengthOfLongestSubstring(string s) {int n = s.size();int l=0, r=0;set<char> S;in

leetcode 刷题之路 8 Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings. 寻找一组字符串的最长公共前缀，比较简单，直接贴上程序： accepted answer: class Solution {public:string longestCommonPrefix(vector<str

Leetcode25: Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings. 求若干字符串的最长公共前缀。首先若无字符串，返回“”；接下来求得其中最短字符串的长度len，比较公共前缀只需最多比较len次；最后比较所有字符串里每一位上的字符。 class Solution {public:s

ZJU2136 Longest Ordered Subsequence

这是一道经典的最长上升子序列问题，首先确定阶段和状态。然而每个阶段仅仅有一个状态，使用一位数组递推。令 dp[i] 表示以 i 结尾的最长上升子序列的长度，则有 dp[i] = { max(dp[j]) + 1 | 0 <= j <i, seq[i] > seq[j] } 边界 dp[0] = 1 表示首个为结尾的最长串长度为1。 #define LOCAL#include <iost

LeetCode | Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings. 求字符串最长公共前缀，这题也没啥好说的，就代码可读性上说一说好了。我写的虽然也是4ms虽然也没错，但是可读性上来说相对差了一点 class Solution {public:string longestComm

LeetCode | Longest Palindromic Substring

题目 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. 最长回文串问题，网上也有超

第五题：最长回文子串(Longest Palindromic Substring)

题目描述：给定一个字符串 s，找到 s 中最长的回文子串。示例：输入：s = "babad" 输出："bab" 或 "aba" 输入：s = "cbbd" 输出："bb" 要求：你需要找出 s 中的最长回文子串。解题思路方法1：中心扩展法回文字符串的特点是对称的，因此我们可以从每个字符（或字符间隙）作为中心，向两边扩展来找到回文子串。遍历每个字符：对于字符串

(LeetCode)Longest Common Prefix --- 最长公共前缀

Write a function to find the longest common prefix string amongst an array of strings. Subscribe to see which companies asked this question 解题分析：首先要理解，如果是空串的话，那么说明前

leetcode 题解 3. Longest Substring Without Repeating Characters

这一题的目标是找出字符串中最长的子串，要求字符串无重复。先是一个错误的解法：首先找出最长的无重复子串从该子串的下一个字母开始，继续执行判断过程。但这一方法存在一定的漏洞，对于其中的测试用例：“dvdf”，如果采用以上思路，则首先得到子串“dv”；再从d开始判断，得到子串“df”，此时处理过程结束。但以上过程并不能得到最优结果“vdf”。因此为解决这种情况，解法又回到了暴力方法。

3. Longest Substring Without Repeating Characters 无重复字符的最长子串

https://leetcode.com/problems/longest-substring-without-repeating-characters/description/ 题目大意:给一个字符串,要求出最长的不含重复字符子串(要求连续,不是子序列). 解题思路:不重复,利用哈希表.hash是以字符的ASC为下标的数组,对应存储该字符最后出现的位置. 设一个标记start,然后一次遍历

[POJ 3764] The xor-longest Path （Tire树 + 贪心）

POJ - 3674 题意是给你一个树，每条边有一个权值，求得树上一条路径，使路径上每条边权值的异或和最大首先用一个 DFS把根到任意点的路径的异或和求出来 xorv[i] 由异或的性质可得点 u和点 v的异或和即为 xorv[u]^xorv[v] （根到两点 LCA的异或和会消去）然后问题就转化成在区间内找两个值，使得他们的异或和最大与 LightOJ - 1269一样的做法，