目录 题目链接 注意点 解法 小结 题目链接 Find Common Characters - LeetCode 注意点 不能单纯的以字母出现的次数来判断是否是公共的字母 解法 解法一:将第一个字符串的每个字母逐个在其他字符串中查找,如果所有的字符串都含有就加入res.时间复杂度O(n^2),n是所有字符串的长度之和. class Solution { public: vector<string> commonChars(vector<string>& A) { vecto…

题目标签:Array, Hash Table 题目给了我们一个string array A,让我们找到common characters. 建立一个26 size 的int common array,作为common characters 的出现次数. 然后遍历每一个 string, 都建立一个 int[26] 的 temp array,来数每个char 出现的次数,当完成了这个str 之后, 把这个temp array 更新到 common 里面去,这里要挑最小的值存入.当完成所有string…

package y2019.Algorithm.array; import java.util.*; /** * @ProjectName: cutter-point * @Package: y2019.Algorithm.array * @ClassName: CommonChars * @Author: xiaof * @Description: 1002. Find Common Characters * Given an array A of strings made only from…

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,…

转自出处 Write a program that gives count of common characters presented in an array of strings..(or array of character arrays) For eg.. for the following input strings..  aghkafgklt  dfghako  qwemnaarkf  The output should be 3. because the characters a,…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 字典 日期 题目地址:https://leetcode.com/problems/find-common-characters/ 题目描述 Given an array A of strings made only from lowercase letters, return a list of all characters that show up…

这是悦乐书的第375次更新,第402篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第236题(顺位题号是1002).给定仅由小写字母组成的字符串A,返回列表中所有字符串都有显示的字符的列表(包括重复字符).例如,如果一个字符在所有字符串中出现3次但不是4次,则需要在最终答案中包含该字符三次. 你可以按任何顺序返回答案.例如: 输入:["bella","label","roller"] 输出:["e"…

题目如下: Given an array A of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including duplicates).  For example, if a character occurs 3 times in all strings but not 4 times, you ne…

python可重集合操作 class Solution(object): def commonChars(self, A): """ :type A: List[str] :rtype: List[str] """ if not A: return [] from collections import Counter ans=Counter(A[0]) for str in A: ans&=Counter(str) ans=list(an…

Given an array A of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including duplicates).  For example, if a character occurs 3 times in all strings but not 4 times, you need to…

Given an array A of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including duplicates).  For example, if a character occurs 3 times in all strings but not 4 times, you need to…

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…

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…

1- 问题描述 Write a function to find the longest common prefix string amongst an array of strings. 2- 思路分析 将数组内每个字串转换为List,每次批量取出各列表对应元素存入新列表,对新列表使用set去重.若set长度为1,说明元素一样,算入前缀. 3- Python实现 class Solution: # @param {string[]} strs # @return {string} def lo…

Write a function to find the longest common prefix string amongst an array of strings. 思路:要去是寻找字符串vector里最长的公有前缀. 1.构造迭代器,遍历vector搜索最小string长度.然后从第一个字符开始进行遍历,如果遇到不一样的字符即返回,全部遍历完毕没问题就把它添加到前缀字符串里. 这样做效率比较差,有待改进. class Solution { public: string longestC…

Given an array A of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including duplicates).  For example, if a character occurs 3 times in all strings but not 4 times, you need to…

参考:https://leetcode.com/problems/find-common-characters/discuss/247573/C%2B%2B-O(n)-or-O(1)-two-vectors 地址:https://leetcode.com/problems/find-common-characters/ vector初始化:vector<int> a(7,3) // 把a初始化为包含7个值为3的int char转化为string:string(1,ch) for (auto s…

题目: Write a function to find the longest common prefix string amongst an array of strings. 题解: 解题思路是,先对整个String数组预处理一下,求一个最小长度(最长前缀肯定不能大于最小长度). 然后以第0个字符串作为参照,从第1个字符串到最后一个字符串,对同一位置做判断,有不同字符串返回当前记录的字符串就行. 我的代码如下,不是那么简洁好看,下面有个整理的更好一些:                   …

Given an array A of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including duplicates).  For example, if a character occurs 3 times in all strings but not 4 times, you need to…

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; }…

Given two arrays, write a function to compute their intersection. Example:Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2]. Note: Each element in the result should appear as many times as it shows in both arrays. The result can be in any ord…

原题链接在这里:https://leetcode.com/problems/intersection-of-two-arrays-ii/ 题目: Given two arrays, write a function to compute their intersection. Example:Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2]. Note: Each element in the result should appe…

请点击页面左上角 -> Fork me on Github 或直接访问本项目Github地址:LeetCode Solution by Swift    说明:题目中含有$符号则为付费题目. 如:[Swift]LeetCode156.二叉树的上下颠倒 $ Binary Tree Upside Down 请下拉滚动条查看最新 Weekly Contest!!! Swift LeetCode 目录 | Catalog 序        号 题名Title 难度     Difficulty  两数之…

Here is my collection of solutions to leetcode problems. Related code can be found in this repo: https://github.com/zhuli19901106/leetcode LeetCode - Course Schedule LeetCode - Reverse Linked List LeetCode - Isomorphic Strings LeetCode - Count Primes…

Given two arrays, write a function to compute their intersection. Example 1: Input: nums1 = [1,2,2,1], nums2 = [2,2] Output: [2,2] Example 2: Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4] Output: [4,9] Note: Each element in the result should appear as…

Contest 121 (题号981-984)(2019年1月27日) 链接:https://leetcode.com/contest/weekly-contest-121 总结:2019年2月22日补充的报告.当时不想写.rank:1093/3924,AC:2/4.还是太慢了. [984]String Without AAA or BBB(第一题 4分)(Greedy, M) 给了两个数字,A 代表 A 个 ‘A’, B 代表 B 个‘B’ 在字符串里面.返回一个可行的字符串,字符串中包含 A…

最近在准备找工作的算法题,刷刷LeetCode,以下是我的解题报告索引,每一题几乎都有详细的说明,供各位码农参考.根据我自己做的进度持续更新中......                              本文地址 LeetCode:Reverse Words in a String LeetCode:Evaluate Reverse Polish Notation LeetCode:Max Points on a Line LeetCode:Sort List LeetCode:Ins…

LeetCode专题-Python实现之第1题:Two Sum LeetCode专题-Python实现之第7题:Reverse Integer LeetCode专题-Python实现之第9题:Palindrome Number LeetCode专题-Python实现之第13题:Roman to Integer LeetCode专题-Python实现之第14题:Longest Common Prefix LeetCode专题-Python实现之第20题:Valid Parentheses Leet…

Hash Table基础 哈希表(Hash Table)是常用的数据结构,其运用哈希函数(hash function)实现映射,内部使用开放定址.拉链法等方式解决哈希冲突,使得读写时间复杂度平均为O(1). HashMap(std::unordered_map).HashSet(std::unordered_set)的原理与Hash Table一样,它们的用途广泛.用法灵活,接下来侧重于介绍它们的应用. 相关LeetCode题: 706. Design HashMap  题解  705. Des…