Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example,Given [100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4. Your algorithm should run in…

Longest Consecutive Sequence Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example,Given [100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4.…

Write a function to find the longest common prefix string amongst an array of strings. 思路:找最长公共前缀 常规方法 string longestCommonPrefix(vector<string> &strs) { ) return ""; ) ]; string ans; ; ) { ; i < strs.size(); i++) { ].size() <= n…

这题要仔细体会下哈希表的用法,要注意的是数组本身是无序的,因此需要向左右进行扩张. 另外这个思路可以进行聚类,把连续的标记为一类. int longestConsecutive(const vector<int> &num) { unordered_map<int, bool> used; for (auto i : num)used[i] = false; ; for (auto i : num) { if (used[i])continue; ; used[i] = t…

描述 输入一个乱序的连续数列,输出其中最长连续数列长度,要求算法复杂度为 O(n) . 输入 54,55,300,12,56 输出 3 通常我们看有没有连续序列时 找某个数有没有的前后的数,比如看到55,我们会下意识找56,57...54,53...这道题做法也是这样. 我的做法是用map映射,键为列表中的每个数,值为1.然后遍历数组,比如数为55,找这个数的前后有没有map映射后值为1的,有的话sum++,为了防止重复遍历需要把遍历过的数的映射值改成-1. class Solution { p…

[LeetCode]Longest Word in Dictionary through Deleting 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/longest-word-in-dictionary-through-deleting/#/description 题目描述: Given a string and a string dictionary, find the longest string in the di…

[SPOJ]Longest Common Substring(后缀自动机) 题面 Vjudge 题意:求两个串的最长公共子串 题解 \(SA\)的做法很简单 不再赘述 对于一个串构建\(SAM\) 另外一个串在\(SAM\)上不断匹配 最后计算答案就好了 匹配方法: 如果\(trans(s,c)\)存在 直接沿着\(trans\)走就行,同时\(cnt++\) 否则沿着\(parent\)往上跳 如果存在\(trans(now,c),cnt=now.longest+1\) 否则,如果不存在可行的…

Problem Link: http://oj.leetcode.com/problems/longest-consecutive-sequence/ This problem is a classical problem where we can reduce the running time by the help of hash table. By given a list of numbers, we can find the longest consecutive sequence b…

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example,Given [100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4. Your algorithm should run in…

写在前面   老粉丝可能知道现阶段的LeetCode刷题将按照某一个特定的专题进行,之前的[贪心算法]已经结束,虽然只有三个题却包含了简单,中等,困难这三个维度,今天介绍的是第二个专题[数组] 数组(Array)是一种线性表数据结构.它用一组连续的内存空间,来存储一组具有相同类型的数据.在每一种编程语言中,基本都会有数组这种数据类型.不过,它不仅仅是一种编程语言中的数据类型,还是一种最基础的数据结构. 贪心算法回顾: [LeetCode]贪心算法--买卖股票的最佳时机II(122) [LeetC…