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> test, distancePoints[2005];
  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. distancePoints[i].clear();
  29. cin >> points[i].first >> points[i].second;
  30. }
  32. for (i = 0; i < n; i++)
  33. {
  34. distancePoints[i].clear();
  35. }
  37. ans = 0;
  39. for (i = 0; i < n; i++)
  40. {
  41. for (j = i+1; j < n; j++)
  42. {
  43. distance = distanceSquare(points[i], points[j]);
  44. distancePoints[i][distance]++;
  45. distancePoints[j][distance]++;
  46. //cout << "Adding " << i << " " << j << " with " << distance << "\n";
  47. }
  48. }
  50. ans = 0;
  52. for (i = 0; i < n; i++)
  53. {
  54. for (auto it: distancePoints[i])
  55. {
  56. ans += it.second*(it.second-1)/2;
  57. }
  58. }
  60. cout << "Case #" << t << ": " << ans << "\n";
  61. }
  63. return 0;
  64. }