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  1. #include <bits/stdc++.h>
  2. #define ll long long
  3. #define nono                     \
  4.         ios::sync_with_stdio(0); \
  5.         cin.tie(0);              \
  6.         cout.tie(0);
  7. using namespace std;
  8. set<int> primes = {3, 5, 7, 11, 13, 17, 19, 23, 29, 31};
  9. void solve(vector<int> ring, int n)
  10. {
  11.         if (ring.size() == n)
  12.         {
  13.                 if (primes.find(ring.back() + ring.at(0)) == primes.end())
  14.                         return;
  15.                 cout << 1 ;
  16.                 for (int i = 1; i < n; i++)
  17.                         cout << " " << ring.at(i);
  18.                 cout << '\n';
  19.                 return;
  20.         }
  21.         for (int circle = 2; circle < n + 1; ++circle)
  22.         {
  23.                 bool flag = 1;
  24.                 for (auto a : ring)
  25.                 {
  26.                         if (a == circle)
  27.                                 flag = 0;
  28.                 }
  29.                 if (primes.find(ring.back() + circle) == primes.end())
  30.                         flag = 0;
  31.                 if (flag)
  32.                 {
  33.                         ring.push_back(circle);
  34.                         solve(ring, n);
  35.                         ring.pop_back();
  36.                 }
  37.         }
  38. }
  39. int main()
  40. {
  41.        // nono;
  42.         int i = 1, n;
  43.         while (cin >> n && n != 0)
  44.         {
  45.             if(i>1) cout << "\n";
  46.             cout<<"Case "<<i++<<":\n";
  47.             vector <int > v;
  48.             v.push_back(1);
  49.             solve(v ,n);
  50.  
  51.         }
  52.  
  53.         return 0;
  54. }
  55.  
Success #stdin #stdout 0.01s 5304KB
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stdin 
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stdout 
Standard output is empty
https://ideone.com/r06nZ1
language:
C++14 (gcc 8.3)
created:
2 years ago
visibility:
public

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