Assignment 4

Write a queue manager, consisting of 3 functions: dumarrive,
dumretrieve, dumfree. The objects to be queued are integer arrays of
length 2. The key is the first element of the array; the second
element of the array is supplied and used by the caller.  The elements
are stored in the queue by the function dumarrive, having the calling
sequence

void dumarrive(int a[2]).


They are retrieved and deleted from the queue by the function
dumretrieve, with the calling sequence

void dumretrieve(int a[2]);

dumretrieve retrieves and deletes the largest element of the queue.


The function dumfree frees all of the memory allocated by the
function dumarrive, so that a subsequent call to dumarrive
will start a new queue; its calling sequence is

void dumfree(void).


The queue is to be stored in a heap, dynamically allocated using the
function call malloc.  The amount of space used by the heap at any
time should not be more than 2000+2*n integer locations, where n is
the number of elements stored in the queue.  In other words, the space
for the heap should be allocated and deallocated at reasonable
intervals.

The functions should communicate with each other via a small number of
global variables.  The functions should be submitted in a file,
which should include the main function that you used for testing, and
the global variables (if any) declared at the top.


The assignment is due on December 8, 2000.