1.  Write a function called switch_letters that takes a string 
as parameter and returns nothing.  The function should switch 
the first and last character in the string.  For example, if 
the string is "cold", then it will become "dolc".  If it is "hot", 
it will become "toh".

2.  Write a function called switch_numbers that takes an input
stream and an output stream as parameters, and returns nothing.
The input and output stream will be associated with files that
are already open.  The file the input stream is associated with
only contains integers.  The function should read all those
numbers into an array, then switch the first and last number
in the array, and put the numbers in the output file in 
the switched order.  

3.  Part A of this question will tell you to write a class.
In that class you should include the prototypes for the 
member functions in the other parts of the question.  Some
parts of this question will need functions from previous
parts.  You must figure out when that is needed.

3A.  Create a class called person, which has private data members
containing the first and last name of the person, plus the person's
height in feet and inches. (5 feet and 9 inches, for example)  

3B.  Write a member function of person called same_height.
It should take another person as parameter, and return true
if the person passed as parameter is the same height as
the person used to call the function.

3C.  Write a member function of person called is_taller.
It should take another person as parameter and return true
if the person used to call the function is taller than the
person passed as parameter.

3D.  Write a nonmember function called get_taller.
It will take two persons as parameters and return
the taller of the those two persons.

4.  Part A of this question will tell you to write a class.
In that class you should include the prototypes for the 
member functions in the other parts of the question.  Some
parts of this question will need functions from previous
parts of the question, and some will also need functions
from the previous question.  You must figure out when that 
is needed.

4A.  Create a class called database, which has private data members
containing an array of persons and the number of persons in that
array.

4B.  Write a member function of database called taller_all that 
takes a person as parameter.  It returns true if that person is 
taller than all the persons in the array.  Otherwise it returns false.

4C.  Write a member function of database called taller_some that 
takes a person as parameter.  It returns true if that person is 
taller than at least one person in the array.  Otherwise it returns false.

4D.  Write a nonmember function called some_not_all that takes
a person and a database as parameters.  It returns true if that
person is taller than somebody in the database but not taller
than everybody.  Otherwise it returns false.

4E.  Write a member function of database called num_same_height
that takes a person as parameter.  It returns the number of
persons in the array that are the same height as that person.