#include #include #include #include #include using namespace std; const int SAMPLES = 500; const int BOUNDS = 50; int N; vector> P; inline double distsq(double dx, double dy) { return dx * dx + dy * dy; } bool check(int x, int y, int r) { double Rsq = r*r; for (int i = 0; i < min(N, SAMPLES); i++) { if (distsq(x - P[i].first, y - P[i].second) > Rsq) { return false; } } return true; } void solve() { cin >> N; P.resize(N); for (int i = 0; i < N; i++) { cin >> P[i].first >> P[i].second; } // Generate valid circles. vector> circles; for (int Ax = 0; Ax <= BOUNDS; Ax++) { for (int Ay = 0; Ay <= BOUNDS; Ay++) { int Ar = 1; while (Ar <= BOUNDS && !check(Ax, Ay, Ar)) { Ar++; } if (Ar <= BOUNDS) { circles.push_back({Ax, Ay, Ar}); } } } // Try for all valid circles. int bestAx = -1, bestAy = -1, bestBx = -1, bestBy = -1, bestR = -1; double bestArea = 999999; for (int a = 0; a < (int)circles.size(); a++) { auto [Ax, Ay, R] = circles[a]; for (int b = a + 1; b < (int)circles.size(); b++) { auto [Bx, By, Br] = circles[b]; if (R != Br) { continue; } double dsq = distsq(Ax - Bx, Ay - By); // Fail if circles don't overlap. if (dsq >= 4 * R * R) { continue; } // Choose the answer that minimizes the area of the overlap. double d = sqrt(dsq); double fouradsq = sqrt((4 * R * R) - dsq); double area = R * R * M_PI; area -= 2 * R * R * atan2(d, fouradsq); area -= 0.5 * d * fouradsq; if (area < bestArea) { bestArea = area; bestAx = Ax; bestAy = Ay; bestBx = Bx; bestBy = By; bestR = R; } } } // Compute sum of squared distance to points from both A and B. // If B's sum is less, B is actually A. // Note: We can afford to use all N points for this, no need to sample. double Asum = 0, Bsum = 0; for (auto [x, y] : P) { Asum += distsq(x - bestAx, y - bestAy); Bsum += distsq(x - bestBx, y - bestBy); } if (Bsum < Asum) { swap(bestAx, bestBx); swap(bestAy, bestBy); } cout << bestAx << " " << bestAy << " " << bestBx << " " << bestBy << " " << bestR << endl; } int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int T; cin >> T; for (int t = 1; t <= T; t++) { cout << "Case #" << t << ": "; solve(); } return 0; }