Perhaps you all have heard the mythical story about Tower of Hanoi (The details of this story is not required to solve this problem): “There is a tower of Hanoi with 64 disks and three pegs and the preists make one move everyday and the earth will be…

Description Perhaps you all have heard the mythical story about Tower of Hanoi (The details of this story is not required to solve this problem): “There is a tower of Hanoi with 64 disks and three pegs and the preists make one move everyday and the e…

输出整数N,使得  t1 <= N  统计有多少组t1,t2,t3,满足:1<t1<t2<t3<=1000000,t3-t1<=25,且t1,t2,t3的最小公倍数是N 枚举t1就好了 #include <iostream> #include <cstdio> #include <sstream> #include <cstring> #include <map> #include <set> #i…

1.LA 5694 Adding New Machine 关键词:数据结构,线段树,扫描线(FIFO) #include <algorithm> #include <cstdio> #include <cstring> #include <string> #include <queue> #include <map> #include <set> #include <ctime> #include <cm…

"在一个全集\(X\)中若干子集的集合为\(S\),精确覆盖(\(\boldsymbol{Exact~Cover}\))是指,\(S\)的子集\(S*\),满足\(X\)中的每一个元素在\(S*\)中恰好出现一次.在计算机科学中,精确覆盖问题指找出这样的一种覆盖,或证明其不存在." \(0x01\) 精准覆盖问题 --其实是一种决策问题,给定\(n\)行长度为\(m\)的\(0,1\)序列,要求选出一些行,使得每一列有且仅有一个\(1\),这就是精准覆盖问题. 诚然,我搜索贼菜,所以暂…

Method ringing is used to ring bells in churches, particularly in England. Suppose there are 6 bells that have 6 different pitches. We assign the number 1 to the bell highest in pitch, 2 to the second highest, and so on. When the 6 bells are rung in…

//: Playground - noun: a place where people can play import UIKit var str = "Hello, playground" enum Movement { case Left case Right case Top case Bottom } let aMovement = Movement.Left switch aMovement { case .Left: print("left") defa…

建议88:用枚举实现工厂方法模式更简洁 工厂方法模式(Factory Method Pattern)是" 创建对象的接口,让子类决定实例化哪一个类,并使一个类的实例化延迟到其它子类".工厂方法模式在我们的开发中经常会用到.下面以汽车制造为例,看看一般的工厂方法模式是如何实现的,代码如下: //抽象产品 interface Car{ } //具体产品类 class FordCar implements Car{ } //具体产品类 class BuickCar implements Ca…

假设我们需要表示网络连接状态,可以用下列枚举表示: enum CSConnectionState { CSConnectionStateDisconnected, CSConnectionStateConnecting, CSConnectionStateConnected, }; 然而定义枚举变量的方式却太不简介,要依如些语法编写: enum CSConnectionState state = CSConnectionStateDisconnected; 若是每次不用敲入 enum 而只需写…

Help Hanzo 题意:求a~b间素数个数(1 ≤ a ≤ b < 231, b - a ≤ 100000).     (全题在文末) 题解: a~b枚举必定TLE,普通打表MLE,真是头疼.. b - a ≤ 100000 是关键. 类似素数筛的方法: 1.初始化vis[]=0 ; 2.素数的倍数vis[]=1; 3.  b较小时,素数筛解决   b很大时,素数筛的vis[]会MLE,此时用vis2[i-a]保存vis[i]就不会MLE 了.. #include<iostream>…