Codeforces 1362B. Johnny and His Hobbies Solution

1. Solution in C++:
   ///**********ALLAH IS ALMIGHTY************///
   ///AH Tonmoy
   ///Department of CSE,23rd batch
   ///Islamic University,Bangladesh
2. #include<iostream>
3. #include<Set>
4. using namespace std;
5. int main()
6. {
7. int t,n,i,j;
8. cin>>t;
9. while(t--)
10. {
11. cin>>n;
12. int ar[n];
13. set<int>s;
14. for(i=0;i<n;i++)
15. {
16. cin>>ar[i];
17. s.insert(ar[i]);
18. }
19. int r=-1;
20. for(i=1;i<=1024;i++)
21. {
22. set<int>s1;
23. s1.clear();
24. for(j=0;j<n;j++)
25. {
26. s1.insert(i^ar[j]);
27. }
28. if(s==s1)
29. {
30. r=i;
31. break;
32. }
33. }
34. cout<<r<<endl;
35. }
36. }