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…

UVA - 524 Prime Ring Problem Time Limit:3000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu 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 number…

  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…

题意  把1到n这n个数以1为首位围成一圈  输出全部满足随意相邻两数之和均为素数的全部排列 直接枚举排列看是否符合肯定会超时的  n最大为16  利用回溯法 边生成边推断  就要快非常多了 #include<cstdio> using namespace std; const int N = 50; int p[N], vis[N], a[N], n; int isPrime(int k) { for(int i = 2; i * i <= k; ++i) if(k % i == 0)…

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 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…

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 42600    Accepted Submission(s): 18885 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): 23458    Accepted Submission(s): 10465 Problem Description A ring is compose of n circles as shown in diagram. Put natural numb…