一.题目回顾 题目链接:Prime Ring Problem Problem Description A ring is compose of n circles as shown in diagram. Put natural number 1, 2, ..., n into each circle separately, and the sum of numbers in two adjacent circles should be a prime. Note: the number of…

/* Name: NYOJ--488--素数环 Author: shen_渊 Date: 15/04/17 15:30 Description: DFS,素数打个表,37以内就够用了 */ #include<cstring> #include<iostream> #include<cstdio> #include<algorithm> using namespace std; void dfs(int); int n; //int prime[25] = {…

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 52146    Accepted Submission(s): 23096 Problem Description A ring is compose of n circles as shown in diagram. Put natural num…

 就是说,给你一个数n, 要你把1到n都连在一起成环. 每一个数不可反复, 且相连的两个数的和要是素数. 把全部情况输出来. 我是用dfs暴力出来的. 首先把素数打表, 然后每次顺时针预測下一个数, 由于这个数必需要是素数减去上一个数, 非常好枚举. 我的代码例如以下: #include<iostream> #include<cstring> #include<cstdlib> using namespace std; int map[30],num,prime[]…

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): 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): 31031    Accepted Submission(s): 13755 Problem Description A ring is compose of n circles as shown in diagram. Put natural numb…

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…

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)…

Prime Ring Problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 20105    Accepted Submission(s): 9001 Problem Description A ring is compose of n circles as shown in diagram. Put natural numb…