这道题是只有四则运算但是没有括号的,因此可以利用stack来存储的,并且每次使得存储的值与符号有对应的关系,最后在栈中只剩下可以利用加法进行处理的数的,注意在i=n-1的时候到达最后的部分也是需要把数字压入栈中的而不能被忽略掉. class Solution { public: int calculate(string s) { ,num=,n=s.size(); stack<int> st; char op='+'; ;i<n;i++){ '){ num=num*+s[i]-'; }…

Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero. You may assume that the given ex…

一.Basic Calculator Total Accepted: 18480 Total Submissions: 94750 Difficulty: Medium Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, …

227. 基本计算器 II 227. Basic Calculator II 题目描述 实现一个基本的计算器来计算一个简单的字符串表达式的值. 字符串表达式仅包含非负整数,+,-,*,/ 四种运算符和空格.整数除法仅保留整数部分. LeetCode227. Basic Calculator II中等 示例 1: 输入: "3+2*2" 输出: 7 示例 2: 输入: " 3/2 " 输出: 1 示例 3: 输入: " 3+5 / 2 " 输出:…

Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, /operators and empty spaces . The integer division should truncate toward zero. Example 1: Input: "3+2*2" Ou…

Atitit HTTP认证机制基本验证 (Basic Authentication) 和摘要验证 (Digest Authentication)attilax总结 1.1. 最广泛使用的是基本验证 (Basic Authentication) 和摘要验证 (Digest Authentication).1 1.2. 关于HTTP AUTH的文档不多.1 1.3. 什么是HTTP基本认证1 1.4. 适用场合 路由器 摄像头2 1.5. 其他认证  除了基本认证(Basic Authenticat…

After learning the basic opreation of Redis,we should take some time to summarize the usage. And I wrote my first edition RedisHelper.Here is the code: The Interface IRedis: public interface IRedis { ITransaction GetTransaction(, bool isRead = false)…

Data play an important part in our project,how can we ensure correctness of the data and prevent the data from error.In relational database, we are famillar with the usage of transaction. begin opreations commit/rollback But there are some difference…

This post is mainly about the publishment and subscription in Redis.I think you may subscribe some offiial accounts on wechat,and when the authors published something new to their accounts,you will get them in your wechat.The instance can make you un…

Redis's List is different from C#'s List,but similar with C#'s LinkedList.Sometimes I confuse with them.I expect that you won't mix them and have a clear mind of them. There are 17 commands we can use in List. Push and pop are the base opreation of t…

The last post is mainly about the unsorted set,in this post I will show you the sorted set playing an important role in Redis.There are many command added after the version 2.8.9.OK,let's see the below picture firstly.There are 24 commands to handle…

This post will introduce you to some usages of Set in Redis.The Set is a unordered set,it means that the data was stored in the database randomly.And there are 15 commands you can use in Redis,the same as Hash. For storing the data to database,we can…

When you first saw the name of Hash,what do you think?HashSet,HashTable or other data structs of C#?As for me, the first time I saw the Hash,I considered is as the HashTable.Actually,Hash can identify with HashTable,the same as DataRow.A row data of…

This post is mainly about how to use the commands to handle the Strings of Redis.And I will show you both the native commands and the usage of the StackExchange.Redis.The version of Redis is 3.2.3 and the vesion of StackExchange.Redis is 1.1.604-alph…

Nowaday, Redis became more and more popular , many projects use it in the cache module and the store module. There are already many people wrote posts about Redis.And I am vary pleasure to join them to share my learing of Redis. But I am new in this…

Source: https://www.medicine.mcgill.ca/physio/vlab/biomed_signals/eeg_n.htm The electroencephalogram (EEG) is a recording of the electrical activity of the brain from the scalp. The recorded waveforms reflect the cortical electrical activity. Signal…

Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero. You may assume that the given ex…

Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the given expression is…

前言:最近,讨论到数据库安全的问题,于是就引出了WebApi服务没有加任何验证的问题.也就是说,任何人只要知道了接口的url,都能够模拟http请求去访问我们的服务接口,从而去增删改查数据库,这后果想想都恐怖.经过一番折腾,总算是加上了接口的身份认证,在此记录下,也给需要做身份认证的园友们提供参考. WebApi系列文章 C#进阶系列——WebApi接口测试工具:WebApiTestClient C#进阶系列——WebApi 跨域问题解决方案:CORS C#进阶系列——WebApi身份认证解决方…

Network Basic Commands Summary set or modify hostname a)     temporary ways hostname NEW_HOSTNAME, but if you reboot your system, it will disabled. b)    permanent ways: edit "/etc/sysconfig/network" HOSTNAME, then restart system, it will effect…

Learning basic Linux commands Command Description $ ls This command is used to check the contents ofthe directory. $ pwd This command is used to check the presentworking directory. $ mkdir work We will work in a separate directory calledwork in our h…

Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero. You may assume that the given ex…

Openpyxl basic function demo code demo code: #!/usr/bin/env python # -*- coding: utf-8 -*- """ summary description - openpyxl basic功能练习 - https://openpyxl.readthedocs.io/en/default/usage.html :REQUIRES: :TODO: :AUTHOR: Pengtao.Fan :ORGANIZA…

原创地址:http://www.cnblogs.com/jfzhu/p/4071342.html 转载请注明出处 如何在WCF中使用Transport Security Mode,以及如何创建证书,请参见<WCF basicHttpBinding之Transport Security Mode, clientCredentialType="None">,本文介绍如何使用Basic clientCredentialType. server web.config <?xm…

很多情况下目标Action方法都要求在一个安全上下文中被执行,这里所谓的安全上下文主要指的是当前请求者是一个经过授权的用户.授权的本质就是让用户在他许可的权限范围内做他能够做的事情,授权的前提是请求者是一个经过认证的用户.质询-应答(Chanllenge-Response)"是用户认证采用的一种常用的形式,认证方向被认证方发出质询以要求其提供用于实施认证的用户凭证,而被认证方提供相应的凭证以作为对质询的应答.旨在目标Action方法执行之前实施身分认证的AuthenticationFilter也…

mongoDB basic from:http://www.tutorialspoint.com/mongodb prject:https://github.com/chenxing12/l4mongodb overview getting-start collection dataType insert find Overview MongoDB is a cross-platform, document oriented database that provides, high perfor…

看到Microsoft官方一篇关于异步编程的文章,感觉挺好,不敢独享,分享给大家. 原文地址:https://msdn.microsoft.com/zh-cn/library/hh191443.aspx 通过使用异步编程,你可以避免性能瓶颈并增强应用程序的总体响应能力. 但是,编写异步应用程序的传统技术可能比较复杂,使它们难以编写.调试和维护. Visual Studio 2012 引入了一个简化的方法(即异步编程),该方法利用 .NET Framework 4.5 和 Windows 运行时中…

先看效果图: 增加: 修改: 删除: 具体实现: html与js代码: @{ Layout = null; } <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Basic CRUD Application - jQuery EasyUI CRUD Demo</title> <link rel="stylesheet"…

当某个页面需要认证才能进行访问时,接到请求后服务器端会在响应头中发送一个 WWW-Authenticate 首部(用来标识认证安全域),语法为 WWW-Authenticate:Basic relam=quoted-string 客户端接收到后会弹出一个对话框,要求输入用户名和密码,用户输入的用户名和密码将会分别保存至 $_SERVER['PHP_AUTH_USER'] 和 $_SERVER['PHP_AUTH_PW'] 中,开发者可以设计程序验证用户输入的用户名和密码是否正确. 当用户输入用户…

在.htaccess文件中增加 AuthUserFile /var/www/htpasswd/test.htpasswd AuthName EnterPassword AuthType Basic require valid-user #htpasswd密码文件生成.Create a password file Filename with username as the initial ID. It will prompt for the password htpasswd -c Filenam…