(2) Write a

CMatrix

class, which represents an

n

x

n

matrix of integers. Such a matrix is

called a square matrix. Note: An ordinary user is going to use your matrix. So to her/him,

the index of row is from 1 to

n

while the index of column is from 1 to

n

as well. But

internally, we know that the array index should be from 0 to n 1. For instance, if s/he

wants to get the element at (5, 4), this element actually corresponds to (4, 3) in your 2D

dynamic array in C++. Please pay attention to this.

Your class should include the following member functions. The member variable is

called

Matrix

, which is a 2D dynamic array, and the member variable

Dimension

represents the dimension of the matrix.

Constructor

:

accepts

n

as a parameter and constructs a matrix of the requested size.

Initialize all entries to 0 and use the default value

n

= 2.

int getDimension()

:

returns the dimension of the matrix.

int getElementAt(int i, int j)

:

returns the element at (

i

,

j

). Use assert to ensure that the

indices are within the valid range.

int replaceElementAt(int i, int j, int newint)

:

replaces the element at (

i

,

j

) and return the

old element at (i, j). Use assert to ensure that the indices are within the valid range.

void swapElementsAt(int i1, int j1, int i2, int i3)

:

swaps between the two elements at

(

i1

,

j1

) and at (

i2

,

j2

). Use assert to ensure that all the indices are within the valid range.

void resizeMatrix(int newsize)

:

resizes the matrix from its original size to the

newsize

.

We can enlarge the original matrix: we copy the original matrix to the new one and set 0

to all the additional elements in the new one. We can also shrink the original matrix: we

copy the elements of the original matrix within the

newsize

to the new one and ignore

those beyond the

newsize

. Use assert to ensure that the

newsize

is valid, i.e., not a

negative number.

void readMatrix():

reads n x n elements from the input using

cin

. For example for a 3 x

3 matrix, the format should be:

Input matrix element at (1, 1): 11

Input matrix element at (1, 2): 2

Input matrix element at (1, 3): 5

Input matrix element at (2, 1): 5

...

Input matrix element at (3, 3): 45

Done reading

void printMatrix():

prints out the elements in the matrix using

cout

. For example, for the

above 3 x 3 matrix, the printout would be formatted to:

1 2 5

5 ... ...

... ... 45

You are required to use a dynamic 2D array to implement the matrix. The declaration of

the class is put into

matrix.h

while the implementation of the class is put into

matrix.cc

.

Create a test program called

testMatrix.cc

. Your test should show that the member

functions of the matrix class work as expected. One good way to do this: create a 4 x 4

array, read elements in it, print it out, change some elements, swap some elements, resize

it to 6 x 6, shrink it to 4 x 4, shrink it to 3 x 4, etc. and etc. Each time when you change

something in the matrix, just print it out to verify (show) that your program works.

You can create two helper functions called

allocateMatrixMemory

and

deallocateMatrixMemory

to dynamically manage the dynamic 2D array

Matrix

. We have

discussed the details of those operations.