base

Converting from a string to a number

由 依然范特西╮ 提交于 2019-12-07 19:23:16
问题 So, I am trying to write a program to decode 6-character base-64 numbers. Here is the problem statement: Return the 36-bit number represented as a base-64 number in reverse order by the 6-character string s where the order of the 64 numerals is: 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-+ i.e. decode('000000') → 0 decode('gR1iC9') → 9876543210 decode('++++++') → 68719476735 I would like to do this WITHOUT strings. The easiest way to do this would be to create the inverse

new operator in function parameter

由 穿精又带淫゛_ 提交于 2019-12-07 18:07:11
问题 I have a function and that function takes in a class pointer. the problem is that I call the class pointer like this. Function (new ChildClass); the function looks something like this void Function (BaseClass *instance) { childClassInstance = instance; } the reason why I call it with the new keyword is because I need it outside my function. What I wanted to know was. When I'm ready to delete instance. How would I go about it? Since it's in the function parameter, how would I go about calling

Convert from one base to another in JavaScript

由 自闭症网瘾萝莉.ら 提交于 2019-12-07 16:50:02
问题 In JavaScript, is there any built-in function for converting an integer from one given base to another given base? I've noticed that it's already possible to convert a decimal number to another base using toString(numberToConvertTo) , but I haven't yet found a general-purpose function that can convert from any base to any other base, as shown: convertFrom(toConvert, baseToConvertFrom, baseToConvertTo){ //convert the number from baseToConvertFrom to BaseToConvertTo } 回答1: Call parseInt(str,

局域网搭建hadoop平台——基于基础镜像通过Dockerfile创建Hadoop镜像

由 泪湿孤枕 提交于 2019-12-07 14:59:38
创建一个base.repo文件 在window机器上创建一个文件base.repo，文件包含内容如下： [base] name=RedHat baseurl=http://172.17.0.2/RedHat gpgcheck=1 gpgkey=http://172.17.0.2/RedHat/RPM-GPG-KEY-redhat-release [updates] name=RedHat baseurl=http://172.17.0.2/RedHat gpgcheck=1 gpgkey=http://172.17.0.2/RedHat/RPM-GPG-KEY-redhat-release [extras] name=RedHat baseurl=http://172.17.0.2/RedHat gpgcheck=1 gpgkey=http://172.17.0.2/RedHat/RPM-GPG-KEY-redhat-release 编写Dockerfile文件 在window编写Dockerfile文件，文件包含如下内容： FROM redhat:7.3 MAINTAINER henni_719 COPY jdk1.8.0_171 /usr/local/jdk1.8.0_171 RUN mkdir /data && mkdir /data/hdfs &&mkdir /data

C++中基类的析构函数为什么要用virtual虚析构函数

由 我怕爱的太早我们不能终老 提交于 2019-12-07 07:09:56
大家知道，析构函数是为了在对象不被使用之后释放它的资源，虚函数是为了实现多态。那么把析构函数声明为vitual有什么作用呢？ 直接的讲， C++中基类采用virtual虚析构函数是为了防止内存泄漏。具体地说，如果派生类中申请了内存空间，并在其析构函数中对这些内存空间进行释放。假设基类中采用的是非虚析构函数，当删除基类指针指向的派生类对象时就不会触发动态绑定，因而只会调用基类的析构函数，而不会调用派生类的析构函数。那么在这种情况下，派生类中申请的空间就得不到释放从而产生内存泄漏。所以，为了防止这种情况的发生，C++中基类的析构函数应采用virtual虚析构函数。 请看下面的代码： #include <iostream> using namespace std; class Base { public: Base() {}; //Base的构造函数 ~Base() //Base的析构函数 { cout << "Output from the destructor of class Base!" << endl; }; virtual void DoSomething() { cout << "Do something in class Base!" << endl; }; }; class Derived : public Base { public: Derived() {}; /

Scala部分应用函数

由 倖福魔咒の 提交于 2019-12-07 06:22:45
scala部分应用函数不仅可以用在普通函数上，也可以用在类的方法上 （1）在普通函数上的应用 def sum(a: Int, b: Int, c: Int) = { a + b + c } val sum1 = sum(_: Int, 2, 3) sum1: Int => Int = <function1> sum1(1) 执行结果：res1: Int = 6 （2）在类方法上的应用 trait Base { def print(msg: String) } class SubOne extends Base { override def print(msg: String): Unit = { println("#In SubOne: " + msg) } } class SubTwo extends Base { override def print(msg: String): Unit = { println("#In SubTwo: " + msg) } } val f = (_: Base).print("Hello") // f: Base => Unit = <function1> val one = new SubOne val two = new SubTwo f(one)<span style="white-space:pre"> </span>// 执行结果：

Generating a constructor that takes an argument and just calls base(argument) using TypeBuilder

由 穿精又带淫゛_ 提交于 2019-12-07 05:19:19
问题 I am trying to dynamically create an empty constructor that takes an argument and simply calls base(argument) using TypeBuilder. My code is something like: (...) // Create a class derived from this class TypeBuilder typeBuilder = moduleBuilder.DefineType("NewClass", TypeAttributes.Class, this.GetType()); ConstructorInfo baseCtor = this.GetType().GetConstructor(new[] { typeof(int) }); // Define new ctor taking int ConstructorBuilder constructorBuilder = typeBuilder.DefineConstructor

How to count the number of digits in numbers in different bases?

由 橙三吉。 提交于 2019-12-07 02:14:55
问题 I'm working with numbers in different bases (base-10, base-8, base-16, etc). I'm trying to count the number of characters in each number. Example Number: ABCDEF Number of digits: 6 I know about the method based on logarithms but I'm facing some problems. This Python script outputs that it failed to calculate the number of digits correctly in 3,969 numbers out of 1,000,000. I think the method that uses logarithms could be rather slow Links: This C program must be very slow (what if I have a

Base class vs Utility class

由 ＊爱你＆永不变心＊ 提交于 2019-12-07 01:31:05
问题 Which of the two should be preferred? There are some methods which are called by class A, B and C. Should those methods be encapsulated in a class D (base of A, B and C) ? OR Should those methods be encapsulated in a class U and other classes creats it's object to use the methods as required. On what basis decision should be taken? Thanks. 回答1: You should make a static utility class. Only use inheritance if it's actually meaningful—if A , B , and C actually are a D . 回答2: I'd base the

freemarker页面如何获取jsp中的request.getContexPath

由 懵懂的女人 提交于 2019-12-06 17:13:37
1.当controller的requestMapping()只有一级目录时（相对于项目名后多一级目录），该controller跳转的页面中引入js时的相对路径就是webapp 此时可以直接 <script src="static/bootstrap-3.3.4/js/bootstrap.min.js"></script> 路径static是webapp下的一级目录。否则（如controller的requestMapping()中为（“xxx/xxx”）），需使用相对路径。 2. freemarker获取系统相对路径(webapp)方式 spring-mvc.xml 中配置 <!-- FreeMarker视图解析 如返回userinfo。。在这里配置后缀名ftl和视图解析器。。 --> <bean id="viewResolverFtl" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.freemarker.FreeMarkerView" /> <property name="suffix" value=".ftl" />
订阅 base