Description A ring is composed of n (even number) circles as shown in diagram. Put natural numbers into each circle separately, and the sum of numbers in two adjacent circles should be a prime. Note: the number of first circle should always be 1. Inp…
A ring is composed of n (even number) circles as shown in diagram. Put natural numbers 1,2,...,n into each circle separately, and the sum of numbers in two adjacent circles should be a prime. Note: the number of first circle should always be 1. Input…
dfs练习题,我素数打表的时候j=i了,一直没发现实际上是j=i*i,以后可记住了.还有最后一行不能有空格...昏迷了半天 我的代码(紫书上的算法) #include <bits/stdc++.h> using namespace std; int bk[110]; int num[110]; int vis[110]; int n; void db() { for(int i=2;i*i<=100;i++) if(!bk[i]) for(int j=i*i;j<=100;j+=i…
{p1,..., pk : p1 < p2 <...< pk} is called a prime k -tuple of distance s if p1, p2,..., pk are consecutive prime numbers and pk - p1 = s . For example, with k = 4 , s = 8 , {11, 13, 17, 19} is a prime 4-tuple of distance 8. Given an interval [a,…
Sieve of Eratosthenes (素数筛选算法) Given a number n, print all primes smaller than or equal to n. It is also given that n is a small number. For example, if n is 10, the output should be “2, 3, 5, 7″. If n is 20, the output should be “2, 3, 5, 7, 11, 13,…
思路:容易得到s[n]=s[n-1]+s[n-2],也就是fib数. 求第k小的fib质数的也就是第k个质数数-2,当k>2时. 在就是s[n]/x%m=s[n]%(x*m)/x. 代码如下: #include<cstdio> #include<algorithm> #include<cstring> #define ll long long #define M 1000005 using namespace std; ll k,x,m; int prime[M]…
Leading and Trailing lightoj 链接:http://lightoj.com/volume_showproblem.php?problem=1282 uva 链接:http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1970 题意:给定 n, k ,求 nk 的前3位和后三位的值. 思路:1.前 3 位:把 nk 转化为…
The smallest number expressible as the sum of a prime square, prime cube, and prime fourth power is 28. In fact, there are exactly four numbers below fifty that can be expressed in such a way: 28 = 22 + 23 + 24 33 = 32 + 23 + 24 49 = 52 + 23 + 24 47…
http://poj.org/problem?id=3126 https://www.bnuoj.com/v3/problem_show.php?pid=3245 题目鬼图 刚开始看到题目的图觉得这题会很鬼,然后看题,发现是水题... 线性筛预处理素数→BFS+记录深度 or 迭代加深 or 分层BFS // <3126.cpp> - 11/01/16 17:31:53 // This file is made by YJinpeng,created by XuYike's black tec…
解题思路:给定一个数,判定它由几个连续的素数构成,输出这样的种数 用的筛法素数打表 Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 20020 Accepted: 10966 Description Some positive integers can be represented by a sum of one or more consecutive…
Prime Distance Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 12811 Accepted: 3420 Description The branch of mathematics called number theory is about properties of numbers. One of the areas that has captured the interest of number th…
Besides the ordinary Boy Friend and Girl Friend, here we define a more academic kind of friend: Prime Friend. We call a nonnegative integer A is the integer B’s Prime Friend when the sum of A and B is a prime. So an integer has many prime friends, fo…
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5104 rimes Problem Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2844 Accepted Submission(s): 1277 Problem Description Given a number n, pleas…
uva10392 Factoring Large Numbers 本文涉及的知识点是,使用线性筛选法得到素数表. Table of Contents 1 题目 2 思路 3 参考 1 题目 ==================== Problem F: Factoring Large Numbers One of the central ideas behind much cryptography is that factoring large numbers is computationall…
Special equations Time Limit:1000MS Memory Limit:32768KB 64bit IO Format:%I64d & %I64u Submit Status Practice HDU 4569 Description Let f(x) = a nx n +...+ a 1x +a 0, in which a i (0 <= i <= n) are all known integers. We call f(x) 0 (mod…
