1. #include<bits/stdc++.h>
  3. #define distanceSquare(a, b) ((a.first - b.first)*(a.first - b.first) + (a.second - b.second)*(a.second - b.second))
  5. using namespace std;
  7. int main()
  8. {
  9. #ifdef VSP4
  10. freopen("input.txt", "r", stdin);
  11. freopen("output.txt", "w", stdout);
  12. #endif // VSP4
  14. int T, t, n, m, x, y, i, j, repeat, distance;
  15. long long int ans;
  16. vector< pair<int, int> > points;
  17. map<int, int> distancePoints;
  19. cin >> T;
  21. for (t = 1; t <= T; t++)
  22. {
  23. cin >> n;
  24. points.resize(n);
  26. for (i = 0; i < n; i++)
  27. {
  28. cin >> points[i].first >> points[i].second;
  29. }
  31. ans = 0;
  33. for (i = 0; i < n; i++)
  34. {
  35. distancePoints.clear();
  37. for (j = 0; j < n; j++)
  38. {
  39. if (i != j)
  40. {
  41. distance = distanceSquare(points[i], points[j]);
  42. distancePoints[distance]++;
  43. //cout << "Adding " << i << " " << j << " with " << distance << "\n";
  44. }
  45. }
  47. for (auto it: distancePoints)
  48. {
  49. ans += it.second*(it.second-1)/2;
  50. }
  51. }
  53. cout << "Case #" << t << ": " << ans << "\n";
  54. }
  56. return 0;
  57. }