1.题目编号
1020
2.简单题意
输出满足相邻的相加是素数的序列
3.思路
运用深度优先搜索,对每种情况进行遍历,
4.感想
和题库中的N皇后问题相近,都是运用深度优先搜索,对每种情况进行遍历
5.代码
#include<iostream>
#include<stdio.h>
#include<cstring>
int prime[]={0,0,1,1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,0,0};
int visited[21];
int value[21];
int n;
void DFS(int step)
{
int i;
if(step == n+1)
{
if(prime[value[step - 1] + 1])
{
for(i = 1;i <= n;i++)
{
printf("%d%c",value[i],i==n?'\n':' ');
}
}
}
else
{
for(i = 2;i <= n;i++)
{
if(!visited[i] && prime[i + value[step-1]])
{
visited[i] = 1;
value[step] = i;
DFS(step+1);
visited[i] = 0;
}
}
}
}
int main(){
int caseNum = 1;
while(scanf("%d",&n) != EOF){
memset(visited,0,n);
printf("Case %d:\n",caseNum);
value[1] = 1;
DFS(2);
printf("\n");
caseNum ++;
}
return 0;
}