using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading; namespace Starter { public enum Comparison { theFirstComesFirst = 1, theSecondComesFirst = 2 } //包含两项的简单集合 public class Pair<T> { //存放两个对象的…
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading; //如果账户金额小于0 触发事件 namespace Starter { public enum Comparison { theFirstComesFirst = 1, theSecondComesFirst = 2 } //包含两项的简单集合 public class Pai…
类可以自下往上调用父类方法,如果需要在父类中根据不同的子类,来调用子类的方法,那么就需要延迟静态绑定.延迟静态绑定用的是保留关键词static. 所谓延迟静态绑定,顾名思义,静态调用时::符号左侧的部分的的绑定是延迟,也就是说不再被解析为定义当前方法所在的类,而是在实际运行时计算的. <?php class People { public static function hungry(){ //static和调用他的类进行静态绑定,然后调用static所绑定的类的eat方法 static::ea…
Time Limit: 4000/2000 MS (Java/Others) Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 3192 Accepted Submission(s): 371 Problem Description You are given a rooted tree of N nodes, labeled from 1 to N. To the ith node a non-negat…
从这个名字的定义提取出两个关键点,第一点静态,也就是说这个功能只适用于静态属性或静态方法.第二点延迟绑定,这个根据下面代码就可以很好的理解 看一下这个例子: class A{ static $name = "Tom"; public function printName(){ echo self::$name."\n"; self::fun(); } static function fun(){ echo "A Class\n"; } } cla…
传送门 Problem Statement You are given a tree where each node is labeled from 1 to n. How many similar pairs(S) are there in this tree? A pair (A,B) is a similar pair if the following are true: node A is the ancestor of node B abs(A−B)≤T Input format: T…