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  1. #include <iostream>
  2. #include <cstdio>
  3. #include <cstring>
  4. #include <cmath>
  5.  
  6. #define mem(a,b) memset(a,b,sizeof(a))
  7. using namespace std;
  8.  
  9. int a[25];
  10. int vis[25];
  11.  
  12.  
  13. bool isPrim(int n)
  14. {
  15.     if(n<4)
  16.         return true;
  17.     if(n%2==0)
  18.         return false;
  19.  
  20.     for(int i=3; i<=sqrt(n); i++)
  21.     {
  22.         if(n%i==0)
  23.             return false;
  24.     }
  25.     return true;
  26. }
  27.  
  28. void DFS(int k,int m)
  29. {
  30.     if(k==m+1)
  31.     {
  32.         if(isPrim(a[k-1]+a[1]))
  33.         {
  34.             for(int i=1; i<=m; i++)
  35.             {
  36.                 printf("%d",a[i]);
  37.                 if(i==m)
  38.                     printf("\n");
  39.                 else
  40.                     printf(" ");
  41.             }
  42.         }
  43.         return;
  44.     }
  45.     for(int i=1; i<=m; i++)
  46.     {
  47.         if(isPrim(a[k-1]+i)&&vis[i]==0)
  48.         {
  49.             a[k]=i;
  50.             vis[i]=1;
  51.             DFS(k+1,m);
  52.             vis[i]=0;
  53.         }
  54.     }
  55. }
  56.  
  57. int main()
  58. {
  59.     int n,ca=1;
  60.     while(scanf("%d",&n)!=EOF)
  61.     {
  62.         printf("Case %d:\n",ca++);
  63.         mem(vis,0);
  64.         a[1]=1;
  65.         vis[1]=1;
  66.         DFS(2,n);
  67.         printf("\n");
  68.     }
  69.     return 0;
  70. }
  71.  
Success #stdin #stdout 0s 4548KB
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4
stdout
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Case 1:
1 2 3 4
1 4 3 2
https://ideone.com/OOWWIj
language:
C++ (gcc 8.3)
created:
3 years ago
visibility:
public

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