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  1. #include <bits/stdc++.h>
  2. #define int long long
  3. using namespace std;
  4.  
  5.  
  6. void solve() {
  7. 	int n;
  8. 	cin>>n;
  9. 	vector<int> v(n+1);
  10. 	int sum=(n*(n+1))/2;
  11. 	map<int,int> mp;
  12. 	for(int i=1;i<=n;i++){
  13. 		mp[i*i]=1;
  14. 	}
  15. 	if(mp.find(sum)!=mp.end()){
  16. 		cout<<-1<<endl;
  17. 		return;
  18. 	}
  19. 	for(int i=1;i<=n;i++){
  20. 		v[i]=i;
  21. 	}
  22. 	sum=0;
  23. 	for(int i=1;i<n;i++){
  24. 		sum+=v[i];
  25.  
  26. 		if(mp.find(sum)!=mp.end()){
  27. 			int a=v[i],b=v[i+1];
  28. 			swap(v[i],v[i+1]);
  29. 			sum-=a;
  30. 			sum+=b;
  31. 		}
  32. 	}
  33. 	for(int i=1;i<=n;i++){
  34. 		cout<<v[i]<<" ";
  35. 	}
  36. 	cout<<endl;
  37.  
  38. }
  39.  
  40. signed main() {
  41.     int t;
  42.     cin >> t;
  43.     while (t--) {
  44.         solve();
  45.     }
  46.     return 0;
  47. }
  48.  
Success #stdin #stdout 0.01s 5288KB
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https://ideone.com/wf4rYQ
language:
C++ (gcc 8.3)
created:
3 days ago
visibility:
public

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