https://en.wikipedia.org/wiki/Fundamental_theorem_of_arithmetic In number theory, the fundamental theorem of arithmetic, also called the unique factorization theorem or the unique-prime-factorization theorem, states that every integer greater than 1[…

Dirichlet's Theorem on Arithmetic Progressions Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 16733   Accepted: 8427 Description If a and d are relatively prime positive integers, the arithmetic sequence beginning with a and increasing…

poj3006 Dirichlet's Theorem on Arithmetic Progressions 很显然这是一题有关于素数的题目. 注意数据的范围,爆搜超时无误. 这里要用到筛选法求素数. 筛选法求素数的大概思路是: 如果a这个数是一个质数,则n*a不是质数.(年轻的孩子们不要纠结于判断a是否为素数) 用一个数组实现就是: memset(prime,true,sizeof(prime)); if (prime[i]) prime[i*j]=false; 部分程序如下: const m…

Dirichlet's Theorem on Arithmetic Progressions Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 13636   Accepted: 6808 Description If a and d are relatively prime positive integers, the arithmetic sequence beginning with a and increasing…

题目地址:http://poj.org/problem?id=3006 刷了好多水题,来找回状态...... Dirichlet's Theorem on Arithmetic Progressions Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 16803   Accepted: 8474 Description If a and d are relatively prime positive integers, t…

Dirichlet's Theorem on Arithmetic Progressions Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 15398   Accepted: 7714 Description If a and d are relatively prime positive integers, the arithmetic sequence beginning with a and increasing…

Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit cid=1006#status//I/0" class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only" style="font-family:Verdana,Arial,sans-serif; f…

http://poj.org/problem?id=3006 #include <cstdio> using namespace std; bool pm[1000002]; bool usd[1000002]; bool judge(int x) { if(usd[x])return pm[x]; usd[x] = true; if(x == 2) return pm[x] = true; if(((x & 1) == 0) || (x < 2))return pm[x] =…

题目大意:a和d是两个互质的数,则序列a,a+d,a+2d,a+3d,a+4d ...... a+nd 中有无穷多个素数,给出a和d,找出序列中的第n个素数 #include <cstdio> int isPrime(int n) { || (n != && n % == )) ; ; i*i <= n; ++i) ) ; ; } int main() { int a,d,n,cun,temp; while(scanf("%d %d %d",&…

题目大意:给出一个等差数列,问这个等差数列的第n个素数是什么. 思路:这题主要考怎样筛素数,线性筛.详见代码. CODE: #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> #define MAX 1000010 using namespace std; int prime[MAX],primes; bool notp[MAX]; int a,d,n;…

简单的暴力筛法就可. #include <iostream> #include <cstring> #include <cmath> #include <cctype> #include <cstdio> #include <cmath> #include <algorithm> #include <numeric> using namespace std; , M = ; bool is[N]; int pr…

题意 给出a d n    给出数列 a,a+d,a+2d,a+3d......a+kd 问第n个数是几 保证答案不溢出 直接线性筛模拟即可 #include<cstdio> #include<cstring> using namespace std; ]; ]; ]; int cnt; void Prime(int n){ cnt=; memset(Is_Primes,,sizeof(Is_Primes)); ;i<=n;i++){ if(!Is_Primes[i]) Pr…

题意: 设一个等差数列,首元素为a,公差为d 现在要求输入a,d,n ,要求找出属于该等差数列中的第n个素数并输出 思路:空间换时间是个主旋律.素数表的生成用素数筛选法.方法是从2开始,对每个目前还标记为素数的数(初始情况下每个数都标记为素数),把它的所有倍数都标记为非素数.这些扫描过去后,一直没被标记的(即保持为素数的)就是所有的素数. 之后的事情就比较简单了,对等差序列中的每个数一个个去查预先生成的素数表,一直数到第n个素数输出即可. #include <iostream> #includ…

http://poj.org/problem?id=3006 #include<stdio.h> #include<math.h> int is_prime(int n) { int i,m; ) ; m = sqrt(n); ; i <= m; i ++) { ) ; } ; } int main() { int a,d,n,i; while(~scanf("%d%d%d",&a,&d,&n)) { ; &&d==…

The Hundred Greatest Theorems The millenium seemed to spur a lot of people to compile "Top 100" or "Best 100" lists of many things, including movies (by the American Film Institute) and books (by the Modern Library). Mathematicians wer…

FTA - 维基百科,自由的百科全书 FTA 维基百科,自由的百科全书   跳转至: 导航. 搜索 FTA可以指: 自由贸易协定(Free Trade Agreement) 自由贸易区(Free Trade Area) 美国联邦交通管理局(Federal Transit Administration) 故障树分析法(Fault Tree Analysis),即在系统设计过程中,通过对可能造成系统故障的各种因素(包括硬件.软件.环境.人为因素等)进行分析,画出逻辑框图(即故障树),从而确定系统故障…

I Proofs1 What is a Proof?2 The Well Ordering Principle3 Logical Formulas4 Mathematical Data Types5 Induction6 State Machines7 Recursive Data Types8 Infinite SetsII Structures9 Number Theory10 Directed graphs & Partial Orders11 Communication Networks…

A prime number p≥2 is an integer which is evenly divisible by only two integers: 1 and p. A composite integer is one which is not prime. The fundamental theorem of arithmetic says that any integer x can be expressed uniquely as a set of prime factors…

本题有两个难点: 1 大量的数据输入.没处理好就超时 - 这里使用buffer解决 2 因子分解的算法 a)暴力法超时 b)使用sieve(筛子),只是当中的算法逻辑也挺不easy搞对的. 数值N因子分解逻辑: 1 保存全部能够sqrt(N)范围内的质素 2 找到能够被N除尽的质素d, 然后用d去除N.使用deg变量,保存度.即有多少个d能够被N除尽 3 用d去乘全部已经找到的因子(包含1),假设度deg大于1.那么循环i从1到deg, 用d*i去乘全部找到的因子 找到全部因子相加,减去N,就是…

An Illustrated Proof of the CAP Theorem The CAP Theorem is a fundamental theorem in distributed systems that states any distributed system can have at most two of the following three properties. Consistency Availability Partition tolerance This guide…

The author has a course on web: http://brickisland.net/DDGSpring2016/ It has more reading assignments and sliders which are good for you to understand ddg. ------------------------------------------------------------- DISCRETE DIFFERENTIAL GEOMETRY :…

https://math.berkeley.edu/~myzhang/qual.html?tdsourcetag=s_pcqq_aiomsg <!-- Page Content --> <div class="container"> <div class="row" style="margin-top: 80px; margin-bottom: 40px;"> <h3 style="text-a…

2ed,  by Timothy Sauer DEFINITION 1.3A solution is correct within p decimal places if the error is less than 0.5 × 10$^{−p}$ .-P29Bisection Method的优点是计算次数(step)是确定的(interval<精度).后面介绍的算法的interval是不确定的, 所以什么时候结束计算呢?不知道.所以定义“stopping criteria’’来决定什么时候结束…

1.Introduction 2.First-order Differential Equations Exercise2.1. Find solutons of the following intial-value problems in $\bbR^2$: (1)$2u_y-u_x+xu=0$ with $u(x,0)=2xe^{x^2/2}$; (2)$u_y+(1+x^2)u_x-u=0$ with $u(x,0)=\arctan x$. Solution: (1)Since $(-1,…

8-18-小练 A.HDU 1172   猜数字 采用枚举~[赤果果的暴力~] 代码: #include <iostream> #include <cstdio> #include <cstring> using namespace std; ],y[],s,ss,vis[],dis[]; ][]; void find(int b,int c) { ]-]) { s++;vis[]=; return; } ]-]) { s++;vis[]=; return; } ]-]…

                                                                             Dirichlet's Theorem on Arithmetic Progressions Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 15245   Accepted: 7641 Description If a and d are relatively prim…

网页排序的任务中,最核心的难点在于判别网页质量. 将互联网上的网页模拟为一个节点,而这个网页的“出链”看做是指向其他节点的一条“有向边”,而“入链”则是其他节点指向这个节点的有向边.这样整个网络就变成了一张有向图.事情到此就显得容易解决了,因为我们用图论中最普通的有向图模型,完成了对此类问题的建模.具体的说,网页质量的评估是遵循以下两个假设的: 数量假设:一个节点(网页)的入度(被链接数)越大,页面质量越高质量假设:一个节点(网页)的入度的来源(哪些网页在链接它)质量越高,页面质量越高 为了将这…

2ed,  by Timothy Sauer DEFINITION 1.3A solution is correct within p decimal places if the error is less than 0.5 × 10$^{−p}$ .-P29Bisection Method的优点是计算次数(step)是确定的(interval<精度).后面介绍的算法的interval是不确定的, 所以什么时候结束计算呢?不知道.所以定义“stopping criteria’’来决定什么时候结束…

▶ 并行计算八字原则:负载均衡,通信极小 ▶ 并行计算基本形式:主从并行.流水线并行.工作池并行.功能分解.区域分解.递归分治 ▶ MPI 主要理念:进程 (process):无共享存储:显式消息传递:松散同步 / 完全异步:SPMD 方式编程 ▶ MPI 的主要实现版本 ● MPICH,Argonne 国家实验室与 Mississippi 州立大学开发,是最早.最流行的实现 ● MVAPICH,Ohio 州立大学开发,基于 MPICH,强调对各类硬件和网络的个性化支持. ● OpenMPI,S…

 algebraically closed field https://en.wikipedia.org/wiki/Algebraically_closed_field As an example, the field of real numbers is not algebraically closed, because the polynomial equation x2 + 1 = 0  has no solution in real numbers, even though all it…