For this problem, you will write a "Point" class in point.hpp and
point.cpp. The Point class will represent a 2-D point (i.e., it has an
x and a y coordinate). The class should have fields for the x and y,
which should be private doubles.

The Point class must have the following public functionality:

  - A default constructor, which initializes the point's x and y to
    0. 

  - The method
      void move(double dx, double dy);
    which increases the point's x by dx, and its y by dy.

  - The method
      double distanceFrom(const Point & p);
    which takes a constant reference to another point and computes the
    distance between the two points. If you do not remember the
    formula for the distance between two points, you should be able to
    find this domain knowledge easily on the internet.

We have provided a main function (in main.cpp), which makes use of
your Point class. Specifically, it reads input from stdin, where the
first line tells it how many Points to create. It then reads one
command per line until end of input, where a command is either 

m pnum dx dy

or

d p1 p2

The first moves the point specified by pnum (which is an int) by
<dx,dy> (which are floats). The second prints the distance between the
points specified by p1 and p2 (which are ints).

We have already provided a sample input (input1.txt) and sample output
(output1.txt). Since the program reads from stdin, and the tests are
in a file, it is useful to use redirection to send the contents of the
input file to the program. If you do not remember how to use
redirection, this is a good time to review the AoP appendix section on
UNIX basics, Redirection and Pipes.