#include #include #include using namespace std; #define EPS (1.0e-15) class Vector3 { public : double x, y, z; Vector3() { x = 0.0; y = 0.0; z = 0.0; } Vector3(double _x, double _y, double _z) { x = _x; y = _y; z = _z; } Vector3 operator+(const Vector3 &v) const { return Vector3(x + v.x, y + v.y, z + v.z); } Vector3 operator-(const Vector3 &v) const { return Vector3(x - v.x, y - v.y, z - v.z); }..