举例: " let length = str.characters.count //截取前四位 )) //截取后2位(两种方法) )) )) //截取中间4位,从第2位开始(二种方法) let start1 = str.index(str.startIndex, offsetBy: ) str = str.substring(from: start1) //取到从第2位开始的所有字符 let end1 = str.index(str.startIndex, offsetBy: ) var sub

题目描述 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", which the length is 3. For "bbbbb" the longest

题目描述 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. 即给定一个字符串,求它的最长回文子串的长度(或者最长回文子串). 解法一 对于一个问题,一定可以找到一个傻的可爱的暴力解法,本题的暴力解法即

Maximum repetition substring Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9458   Accepted: 2915 Description The repetition number of a string is defined as the maximum number R such that the string can be partitioned into R same conse

Find the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears no less than k times. Example 1: Input: s = "aaabb", k = 3 Output: 3 The longest substring is "aaa"

public String substring(int beginIndex, int endIndex) 返回一个新字符串,它是此字符串的一个子字符串.该子字符串从指定的 beginIndex 处开始,直到索引 endIndex - 1 处的字符.因此,该子字符串的长度为 endIndex-beginIndex. 示例: "hamburger".substring(4, 8) returns "urge" "smiles".substring(

1.jquery  data(name) data() 方法向被选元素附加数据,或者从被选元素获取数据. $("#btn1").click(function(){ $("div").data("greeting", "Hello World"); }); $("#btn2").click(function(){ alert($("div").data("greeting&quo

题目来自 https://leetcode.com/problems/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. 给一个字符串

吐槽-使用清理软件整理电脑要注意,不要清理的"太狠",不然你会受伤的! C#中的Substring() 示例 实现代码 using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks; namespace WindowsDemo{    class Program    {        static void Main(stri

万恶的输入法,在sublime中会显示出繁体字,各位看官见谅. 1.slice()方法:该方法在数组和string对象中都拥有. var a = [1,2,3,4,5,6]; var s = 'this is a string'; console.log(a.slice(1,3));//結果為 [2,3]; console.log(a.slice(-1);//結果為6; console.log(s.slice(1,3));//結果為 hi; console.log(s);//結果為 this i

SQL 中的 substring 函数是用来截取一个栏位资料中的其中一部分. 例如,我们需要将字符串'abdcsef'中的'abd'给提取出来,则可用substring 来实现: ,) 结果: 'abd' 括号中数字'1'表示截取的起始位置是从该字符串第一个字符开始,'3'表示截取后得到的字符串长度为3个字符. 这是'substring'最基础的语法,当然,我们的需求有时候会变得比较复杂,例如以下例子: 我们只想要得到'roomno'中的房间号,发现起始字符位置并不是固定的,而且,我们需要的房间

Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed 100

Given a string, find the length of the longest substring T that contains at most k distinct characters. For example, Given s = “eceba” and k = 2, T is "ece" which its length is 3. 这道题是之前那道Longest Substring with At Most Two Distinct Characters的拓展

Given a string S, find the length of the longest substring T that contains at most two distinct characters.For example,Given S = “eceba”,T is “ece” which its length is 3. 这道题给我们一个字符串,让我们求最多有两个不同字符的最长子串.那么我们首先想到的是用哈希表来做,哈希表记录每个字符的出现次数,然后如果哈希表中的映射数量超过两

Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n). For example,S = "ADOBECODEBANC"T = "ABC" Minimum window is "BANC". Note:If there is no such window i

You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concatenation of each word in words exactly once and without any intervening characters. For example, giv

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. 这道题让我们求最长回文子串,首先说下什么是回文串,就是正读反读都一样的字符串,比如 "bob", "level", &q

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

MySQL 字符串截取函数:left(), right(), substring(), substring_index().还有 mid(), substr().其中,mid(), substr() 等价于 substring() 函数,substring() 的功能非常强大和灵活. 1. 字符串截取:left(str, length) mysql> select left('example.com', 3);+-------------------------+| left('example.

2555: SubString Time Limit: 30 Sec  Memory Limit: 512 MBSubmit: 1936  Solved: 551[Submit][Status][Discuss] Description 懒得写背景了,给你一个字符串init,要求你支持两个操作    (1):在当前字符串的后面插入一个字符串    (2):询问字符串s在当前字符串中出现了几次?(作为连续子串)    你必须在线支持这些操作. Input 第一行一个数Q表示操作个数    第二行一

这算是一道经典的题目了,最长回文子串问题是在一个字符串中求得满足回文子串条件的最长的那一个.常见的解题方法有三种: (1)暴力枚举法,以每个元素为中心同时向左和向右出发,复杂度O(n^2): (2)动态规划法,复杂度O(n^2).设f[i][j]表示[i,j]之间最长回文子串,递推方程见链接. 对于暴力枚举的方法,这里有一个简单的Java实现,要好好理解. public String longestPalindrome(String s) { int start = 0, end = 0; in