HDU 4617

#include <cstring>#include <cstdio>#include <algorithm>#include <iostream>#include <cmath>using namespace std;const int maxn = 305;const double eps = 1e-6;#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1struct Point {double x, y, z;void read() {scanf("%lf%lf%lf", &x, &y, &z);}Point(double x = 0, double y = 0, double z = 0) :x(x), y(y), z(z) {}double operator *(const Point& t) const {return x * t.x + y * t.y + z * t.z;}Point operator ^(const Point& t) const {return Point(y * t.z - t.y * z, z * t.x - t.z * x, x * t.y - t.x * y);}Point operator -(const Point& t) const {return Point(x - t.x, y - t.y, z - t.z);}Point operator +(const Point& t) const {return Point(x + t.x, y + t.y, z + t.z);}double norm() {return sqrt(x * x + y * y + z * z);}void unit() {double t = this->norm();x /= t;y /= t;z /= t;}double dis(const Point& t) const {double a, b, c;a = x - t.x;b = y - t.y;c = z - t.z;return sqrt(a * a + b * b + c * c);}};int dblcmp(double x) {if (x < -eps)return -1;return x > eps;}Point center[maxn];Point A[maxn], B[maxn];Point u[maxn], v[maxn], dir[maxn];double radius[maxn];double cal(int p, int q) {Point tmp = center[p] - center[q];Point n = dir[p] ^ dir[q];n.unit();return fabs(n * tmp);}bool solve(int n, double& ans) {int i, j;double d, p;ans = 1e50;for (i = 0; i < n; ++i) {for (j = i + 1; j < n; ++j) {d = radius[i] + radius[j];p = cal(i, j);if (dblcmp(p - d) <= 0) {return true;} elseans = min(ans, p - d);}}return false;}int main() {int n, i;int T;scanf("%d", &T);while (T--) {scanf("%d", &n);for (i = 0; i < n; ++i) {center[i].read();A[i].read();B[i].read();u[i] = A[i] - center[i];v[i] = B[i] - center[i];dir[i] = u[i] ^ v[i];radius[i] = center[i].dis(A[i]);}double ans;bool flag = solve(n, ans);if (flag)puts("Lucky");else {printf("%.2f\n", ans);}}return 0;}