标签：write ase repr oid res blank pac print return
Inputn (0 < n < 20).
OutputThe output format is shown as sample below. Each row represents a series of circle numbers in the ring beginning from 1 clockwisely and anticlockwisely. The order of numbers must satisfy the above requirements. Print solutions in lexicographical order.
You are to write a program that completes above process.
Print a blank line after each case.
Sample Input
6 8
Sample Output
Case 1: 1 4 3 2 5 6 1 6 5 2 3 4 Case 2: 1 2 3 8 5 6 7 4 1 2 5 8 3 4 7 6 1 4 7 6 5 8 3 2 1 6 7 4 3 8 5 2
思路：DFS遍历所有结果
AC Code:
#include<iostream> #include<cstdio> #include<cstring> using namespace std; int N; int a[21]; int vis[21]; int p[17]={2,3,5,7,11,13,17,19,23,29,31,37,39,41,43,47}; bool prime(int x){ for(int i=0;i<17;i++) if(p[i]==x) return true; return false; } void dfs(int k){ if(k==N&&prime(a[1]+a[N])){ for(int i=1;i<N;i++) printf("%d ",a[i]); printf("%d\n",a[N]); } else{ for(int i=2;i<=N;i++){ if(!vis[i]&&prime(i+a[k])){ vis[i]=1; a[k+1]=i; dfs(k+1); vis[i]=0;//取消标记 } } } } int main(){ int k=1; while(~scanf("%d",&N)){ memset(vis,0,sizeof(vis)); a[1]=1;vis[1]=1; printf("Case %d:\n",k++); dfs(1); printf("\n"); } }
标签：write ase repr oid res blank pac print return
原文地址：https://www.cnblogs.com/astonc/p/9900721.html
