Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 34609    Accepted Submission(s): 15327 Problem Description A ring is compose of n circles as shown in diagram. Put natural numb…

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 40339    Accepted Submission(s): 17813 Problem Description A ring is compose of n circles as shown in diagram. Put natural num…

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 66391    Accepted Submission(s): 28456 Problem Description A ring is compose of n circles as shown in diagram. Put natural numb…

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 74594    Accepted Submission(s): 31690 Problem Description A ring is compose of n circles as shown in diagram. Put natural numb…

dfs,用全局数组和变量保存并更新当前状态. 答案可以直接在搜索结束时打印,n为奇数时方案数为0. acm.hdu.edu.cn/showproblem.php?pid=1016 #include <cstdio> #include <cstring> using namespace std; ; int n; int ans[maxn], k; ]; ]; void init(){ memset(isprime, , sizeof isprime); isprime[] = is…

本文链接:http://www.cnblogs.com/Ash-ly/p/5398684.html 题意: 给你一个数字N(N <= 20),要求你把这N个数组成一个环,环内的数字不能重复,左右相邻的两个的和是素数.给出最后的答案. 思路: 利用回溯剪枝算法,N个数,每个数有N种状态,枚举这N个状态,枚举过程中剪枝优化. 代码: #include <cstdio> #include <iostream> #include <cstring> #include &l…

Prime Ring Problem 思路:先看成一条链,往里头填数,满足任意相邻两数和为质数(这可以打表预处理出40以内的所有质数,扩展的时候枚举),填完了后检查首尾是否满足条件.字典序可以采用扩展时从小到大枚举.另外注意对于每个case多输出一个换行,行末不要有空格. #include<bits/stdc++.h> using namespace std; int n,cnt,a[25]; bool p[45],vis[25]; void print() { for(int i=1;i&l…

题目OJ地址: https://www.luogu.org/problemnew/show/UVA524 hdu oj 1016:  https://vjudge.net/problem/HDU-1016 zoj 1457  :https://vjudge.net/problem/ZOJ-1457 题意翻译 输入正整数n,把整数1,2,...,n组成一个环,使得相邻两个整数之和均为素数.输出时,从整数1开始逆时针排列.同一个环恰好输出一次.. 多组数据,读入到EOF结束. 第i组数据输出前加上一…

  Prime Ring Problem  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…

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 18313    Accepted Submission(s): 8197 Problem Description A ring is compose of n circles as shown in diagram. Put natural numbe…