HDU4741

#include 
#include 
#include 
#include 

#define eps 1e-8
#define zero(x) (((x)>0 (x):-(x))> T;
    while (T--)
    {
        point3 a, b, c, d;
        cin >> c.x >> c.y >> c.z >> d.x >> d.y >> d.z >> a.x >> a.y >> a.z >> b.x >> b.y >> b.z;
        cout << fixed << setprecision(6) << linetoline(a, b, c, d) << endl;

        double H = b.x - a.x, I = b.y - a.y, J = b.z - a.z;
        double K = d.x - c.x, L = d.y - c.y, M = d.z - c.z;
        double N = H * I * L - I * I * K - J * J * K + H * J * M;
        double O = H * H * L - H * I * K - I * J * M + J * J * L;
        double P = H * J * K - H * H * M - I * I * M + I *J * L;
        double Q = -a.x * N + a.y * O - a.z * P;
        double k = (O * c.y - N * c.x - P * c.z - Q) / (N * K - O * L + P * M);
        cout << fixed << setprecision(6) << K * k + c.x << ' ' << L * k + c.y << ' ' << M * k + c.z << ' ';
        swap(a, c);
        swap(b, d);
        H = b.x - a.x, I = b.y - a.y, J = b.z - a.z;
        K = d.x - c.x, L = d.y - c.y, M = d.z - c.z;
        N = H * I * L - I * I * K - J * J * K + H * J * M;
        O = H * H * L - H * I * K - I * J * M + J * J * L;
        P = H * J * K - H * H * M - I * I * M + I *J * L;
        Q = -a.x * N + a.y * O - a.z * P;
        k = (O * c.y - N * c.x - P * c.z - Q) / (N * K - O * L + P * M);
        cout << fixed << setprecision(6) << K * k + c.x << ' ' << L * k + c.y << ' ' << M * k + c.z << endl;
    }
}