Question

In this assignment, you are asked to:

1. create a Matrix class that stores and operate on a dynamic two-dimensional array. The class has the following structure:

Private member variables:

- int ** mat;

- int rows;

- int cols;

Public member functions:

+Default constructor: sets both rows and cols to 3 and creates 3x3 matrix dynamically

+Parameterized constructor: sets the rows and cols to the values passed to the constructor and create a matrix with the given dimensions.

+Destructor: deallocates the dynamically-allocated array. Make sure to delete both dimensions.

+AcceptValues: fill the array with values from the user.

+PrintValues: prints the matrix elements.

+int ** GetMatrix (): returns mat

+void AddMatrix (Matrix & b ): Accepts a Matrix object b by REFERENCE and adds it to the current Matrix. The two matrices are assumed to have the same dimensions. When adding two matrices, every two elements that are at the same position are added together. The following is an example of how this function is called:

Matrix a (2,3);

Matrix b(2,3);

a.AcceptValues();

b.AcceptValues();

a.AddMatrix (b); // the result is stored in a.

a.PrintValues(); // a now has the some of both matrices

2. Create a main where you implement the above example usage of the class.

Answer 1

Following is the code implementation:

Output is as follows:

Following are the lines of code in the program:

#include<iostream>
#include<bits/stdc++.h>
using namespace std;

class Matrix
{
private:int **mat;
int rows;
int cols;

public: Matrix() //this is the default constructor which initializes the value of rows and //column to be 3 by default
{
rows=3;
cols=3;
mat=new int*[rows];
for(int i=0;i<rows;i++)
{
mat[i]=new int[cols];
}
}

Matrix(int r,int c) //this is the parameterized constructor that accepts accepts parameter
{
rows=r;
cols=c;
mat=new int*[rows];
for(int i=0;i<rows;i++)
{
mat[i]=new int[cols];
}
}

~Matrix() //this destructor runs at the end for each object and deallocates memory
{
for(int i=0;i<rows;i++)
{
delete [] mat[i];
}
delete [] mat;
}

void AcceptValues()
{
cout<<"Enter the value for the matrix \n";
for(int i=0;i<rows;i++)
{
for(int j=0;j<cols;j++)
{
cin>>mat[i][j];
}
}
}

void PrintValues()
{
cout<<"The matrix is as follows \n";
for(int i=0;i<rows;i++)
{
for(int j=0;j<cols;j++)
{
cout<<mat[i][j]<<" ";
}
cout<<"\n";
}
}

int **GetMatrix()
{
return mat;
}

void AddMatrix(Matrix &b) //here the object b is passed by reference and in order to refer to the //matrix "a" we use "this" operator
{
for(int i=0;i<rows;i++)
{
for(int j=0;j<cols;j++)
{
this->mat[i][j]=this->mat[i][j]+b.mat[i][j];
}
}
}
};

int main()
{
Matrix a(2,3);
Matrix b(2,3);
a.AcceptValues();
b.AcceptValues();
a.AddMatrix(b);
a.PrintValues();
return 0;
}