Advanced Arrays
---------------

A 2-dimensional array consists of both rows and columns of elements.  For
example the array of numbers

	8	16	9	52
	3	15	27	6
	14	25 	2	10

is called a 2-dimensional array.  The first row contains: 8, 16, 9 and 52.
The second row: 3, 15, 27, 6.  The third row: 14, 25, 2, 10.  The first
column contains: 8, 3, 14.  The rest is obvious.  Each of the elements is 
accessed starting with the 0th position and ending with the (n-1)th position.
If the array is defined such as this:

	int name[row][cols]

Then the above table would be defined like this:

	int name[3][4];

There are 3 rows and 4 columns.  To access the upper left element, the command
is:
	name[0][0]

The lower left element is:

	name[2][0]

The upper right element is:

	name[0][3]

The rest is quite intuitive.  2-dimensional arrays are useful for assignments
with loops.  The (i, j)th position in the table can be index with a set of 
nested loops.  For example:

	for(i = 0; i < 3; i++)
	  for(j = 0; j < 4; j++)
	    name[i][j] = 0;

This set of loops clearly assigns each element of the array to 0.  There is
another way to do this assignment.  That is by using the array initialization
at declaration time like this:

	int name[3][4] = {{0, 0, 0, 0},
			  {0, 0, 0, 0},
			  {0, 0, 0, 0}};


Problem #4 of Exercises 7.4
---------------------------

Write a C function that adds respective values of two 2-dimensional arrays
named "first" and "second", respectively.  Both arrays have two rows and
three columns.  The arrays are of type integer.  The array "first" should
be initialized by:

	int first[2][3] = {{16, 18, 23},
			   {54, 91, 11}};

The array "second" should be initialized by:

	int second[2][3] = {{24, 52, 77},
			    {16, 19, 59}};

Solution:

	Use those declarations above and the following:

	int sum[2][3];
	int i,j;

	for(i = 0; i < 2; i++)
	  for(j = 0; j< 3; j++)
	    sum[i][j] = first[i][j] + second[i][j];