在传统的代码库中,我们常常会看到一些违反了SRP原则的类.这些类通常以Utils或Manager结尾,有时也没有这么明显的特征而仅仅是普通的包含多个功能的类.这种God类还有一个特征,使用语句或注释将代码分隔为多个不同角色的分组,而这些角色正是这一个类所扮演的.  久而久之,这些类成为了那些没有时间放置到恰当类中的方法的垃圾桶.这时的重构需要将方法分解成多个负责单一职责的类. public class CustomerService { public Double CalculateOrderD…

理解:本文中的”去除上帝类”是指把一个看似功能很强且很难维护的类,按照职责把自己的属性或方法分派到各自的类中或分解成功能明确的类,从而去掉上帝类. 详解:我们经常可以在一些原来的代码中见到一些类明确违反了SRP原则(单一原则),这些类通常以“Utils”或“Manager”后缀结尾,但有时这些类也没有这些特征,它仅仅是多个类多个方法的组合.另一个关于上帝类的特征是通常这些类中的方法被用注释分隔为不同的分组.那么久而久之,这些类被转换为那些没有人愿意进行归并到合适类的方法的聚集地,对这些类进行重构…

1.题目 27. Remove Element——Easy Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1)…

# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 27: Remove Elementhttps://oj.leetcode.com/problems/remove-element/ Given an array and a value, remove all instances of that value in place and return the new length.The order of elements ca…

27. Remove Element[leetcode] Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can b…

eclipse使用maven打包时去掉测试类 在pom.xml文件中增加如下配置: <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <configuration> <skip>true</skip> </configuration> </plu…

建议147:重构多个相关属性为一个类 若存在多个相关属性,就应该考虑是否将其重构为一个类.查看如下类: class Person { public string Address { get; set; } public string ZipCode { get; set; } public string Mobile { get; set; } public string Hotmail { get; set; } //其他省略 } 上面代码中的这四个属性全部跟联系方式有关,所以,我们应该重构一…

27. Remove Element[easy] Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be ch…

Given a non-negative integer num represented as a string, remove k digits from the number so that the new number is the smallest possible. Note: The length of num is less than 10002 and will be ≥ k. The given num does not contain any leading zero. Ex…

Problem: Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be changed. It doesn'…

Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be changed. It doesn't matter…

上篇文章提到了误差分析以及设定误差度量值的重要性.那就是设定某个实数来评估学习算法并衡量它的表现.有了算法的评估和误差度量值,有一件重要的事情要注意,就是使用一个合适的误差度量值,有时会对学习算法造成非常微妙的影响.这类问题就是偏斜类(skewed classes)的问题.什么意思呢.以癌症分类为例,我们拥有内科病人的特征变量,并希望知道他们是否患有癌症,这就像恶性与良性肿瘤的分类问题.假设y=1表示患者患有癌症,假设y=0表示没有得癌症,然后训练逻辑回归模型.假设用测试集检验了这个分类模型,并…

27. Remove Element Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memor…

Given a non-negative integer num represented as a string, remove k digits from the number so that the new number is the smallest possible. Note: The length of num is less than 10002 and will be ≥ k. The given num does not contain any leading zero. Ex…

Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The order of ele…

Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be changed. It doesn't matter…

和remove zero类似的方法完成该题 class Solution { public: int removeElement(vector<int>& nums, int val) { vector<; ; i < nums.size(); ++i){ if(nums[i] != val) nums[j++] = nums[i]; } return j; } };…

Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. Solution 1: int removeElement(vector<int>& nums, int…

基于c2的wiki条目.Los Techies的Chris Missal同样也些了一篇关于反模式的post.  简单地说,当你使用大量的嵌套条件判断时,形成了箭头型的代码,这就是箭头反模式(arrowhead antipattern).我经常在不同的代码库中看到这种现象,这提高了代码的圈复杂度(cyclomatic complexity). 下面的例子演示了箭头反模式 ) { if (SecurityChecker.CheckPermission(user, permission) || exe…

在代码中,通常需要一些复杂的对象创建工作,以使这些对象达到一种可以使用的状态.通常情况下,这种创建不过是新建对象实例,并以我们需要的方式进行工作.但是,有时候这种创建对象的需求会极具增长,并且混淆了创建对象的原始代码.这时,工厂类就派上用场了.关于工厂模式更全面的描述可以参考这里.最复杂的工厂模式是使用抽象工厂创建对象族.而我们只是使用最基本的方式,用一个工厂类创建一个特殊类的实例.来看下面的代码: public class PoliceCarController { public Police…

类内部可以有另一个类,也就是内部类,如果带static则为静态内部类静态内部类当然不能直接访问实例变量内部类修饰符可以有四种,而外部类只有两种 内部类的意义:这个内部类只适用于这个外部类因为外部类的某些字段是private的,这个内部类要想访问除非是他的成员生成的class文件也会在一起的,便于整理 内部类作为类的成员,当然也要有外部类的对象才能访问静态内部类的使用,相当于包名 OuterClass.StaticNestedClass nestedObject = new OuterClass.…

类的定义:修饰符,class,类名,extends,逗号分隔的implements,类体{}规范的类名:首字母要大写,以后每个单词首字母都大写字段的定义:修饰符,类型,字段名按照封装的思想,字段通常定义为private,然后提供public方法来访问和修改他们方法的定义:修饰符,返回类型,方法名,(参数列表,逗号分隔,或为空),异常声明throws,方法体{}方法的signature(签名)包括方法名称,参数数量,类型,顺序所以只是返回类型不同的两个方法是通不过编译的规范的方法名:首单词为动词,…

题目描述: Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 解题思路: 遍历即可. 代码如下: public int removeElement(int[] nu…

Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 题目的要求大概是给定一个数组和一个值,删除数组中所有和该值相同的元素并返回一个新的长度 说一下思路: 可以采用双指…

Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be changed. It doesn't matter…

Description: Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be changed. It do…

Given an array and a value, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The order of elements can…

一天一道LeetCode系列 (一)题目 Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can be change…

Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The order of ele…

Given an array and a value, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The order of elements can…