cs1311
                                  spring 2001                  
				  100.0 points


                        due 09:00:00 AM  Feb 16, 2001                 


   Please make sure that ALL essays, short answers, definitions, and
   explanations are in your own words.  NO credit will be given for
   answers taken directly from the book, lecture notes, etc...

   Turn in this assignment electronically using WebWork

   NOTE: You may use any module/data type declarations
         from a previous problem from the same assignment when 
	 answering questions.



[p1]
15.0 points

Node definesa record
  data isoftype Num
  next isoftype Ptr toa Node
endrecord

Create a recursive module that will accept a pointer to a linked list
of numbers and return the mean of the numbers.

Hint: if you defined a record containing a sum and count, could this 
be a function?


[p2]
15.0 points

Player definesa record
	name iot String
	age iot Num
	jersey iot Num
endrecord

P_Node definesa record
  data isoftype Player
  next isoftype Ptr toa P_Node
endrecord

Create a recursive module that will accept a pointer to a linked list 
of players and delete all of the players younger than 30 from that 
list.

[p3]
20.0 points

We need to print a player listing in order of jersey number, using the
declarations from p2.

a. Write a recursive module that will insert an already-filled player
   record into a linked list of players.  Your module must insert the 
   new record in order of jersey number.  Assume the list is already 
   sorted based on the jersey number.

b. Write a module that prints a player record.

c. Write a module which prints all of the players in a linked list.
   Assume the list has been filled with proper player records.


[p4]
20.0 points

Assume that you have the code which implements a Queue as given in 
[Lecture notes pp 59-63] of Student_Recs.  

The declarations will be the same as the notes except the Node used 
will contain Student_Recs.  You may also assume that a module exists 
for printing one Student_Rec:

procedure Print_Student( s iot in Student_Rec)

Write a recursive module which, given a Queue of Student_Recs, will 
pop each record off that Queue and print the record content.

[p5]
30.0 points

Assume that you have the Queue code in p4, and a procedure for filling
a Student_Rec:

procedure Read_Student( s iot out Student_Rec )

a. Write a module which will recursively ask the user for an action that
   can be specified as "Enqueue", "Dequeue", or "End".  

      - If the action is "End", print all of the students remaining in 
        the queue and then terminate the program. [Hint: look at p4.]

      - If the action is "Enqueue", fill a new Student_Rec and enqueue 
        it onto your Queue.  

      - If the action is "Dequeue", dequeue a Student_Rec and print it out.

b. Write an algorithm that will define a Queue of Student_Recs, initialize
   it to be empty, and then call the module from part a. to manipulate the
   Queue.

c. Show the printout when the user enters the following sequence of commands:

	Enqueue Fred 12345 3.4
        Enqueue Mary 23456 2.8
	Dequeue
	Enqueue George 13579 2.4
	Enqueue Annie 24680 3.6
	Enqueue Margaret 12472 4.05
	Enqueue Joe 21537 3.7
	Dequeue
	Dequeue
	Enqueue John 31530 1.8
	End