Exercise "vector3d"

1. Build a struct

   public struct vector3d{public double x,y,z;/*...*/}

   to work with 3-dimensional Euclidean vectors; implement the relevant methods and overload the relevant operators; override ToString method.
2. Implement the members .x,.y,.z as properties.
3. Implement interface ivector3d and implement dot- and vector-product via the interface.

Hints:

• Put the source code in vector3d.cs file and compile it into a library,

  vector3d.dll: vector3d.cs
  	mcs -target:library -out:$@ @<
  

• Your main class with the Main method (which should prove that your vector3d works as intended) should then be compiled as

  main.exe: main.cs vector3d.dll
  	mcs -target:exe -out:$@ -reference:$(word 2,$^) @<
  

• //constructors
  public vector3d(double a,double b,double c){x=a;y=b;z=c;}
  

• //operators
  vector3d operator*(vector3d v, double c){return new vector(c*v.x,c*v.y,c*v.z);}
  vector3d operator*(double c, vector3d v){/*...*/}
  vector3d operator+(vector3d u, vector3d v){/*...*/}
  vector3d operator-(vector3d u, vector3d v){/*...*/}
  //methods
  double dot_product(vector3d other){/*...*/}
  vector3d vector_product(vector3d other){/*...*/}
  double magnitude(){}
  /*...*/