MATRIX ADDITION using DYNAMIC and COPY CONSTRUCTORS

7. Write a program to add two matrices of same copy. Create two objects of the class and each of which refers one 2D matrix. Use constructor to allocate memory dynamically and use copy constructor to allocate memory when one array object is used to initialize another.

// MATRIX ADDITION using DYNAMIC and COPY CONSTRUCTORS

#include<iostream.h>

class matrix

{

            int **a;

public:

            matrix()           // Dynamic Constructor

            {

                        int i,j;

                        a=new int*[3];

                        for(i=0; i<3; i++)

                                    a[i]=new int[3];

                        cout<<"Enter elements for a 3x3 matrix:\n";

                        for(i=0; i<3; i++)

                        for(j=0; j<3; j++)

                                    cin>>a[i][j];

            }

            matrix(matrix & x)     // Copy Constructor

            {

                        int i,j;

                        a=new int*[3];

                        for(i=0; i<3; i++)

                                    a[i]=new int[3];

                        for(i=0; i<3; i++)

                        for(j=0; j<3; j++)

                                    a[i][j]=x.a[i][j];

            }

            ~matrix()                    // Destructor

            {

                        int i;

                        for(i=0; i<3; i++)         delete a[i];

                        delete a;

            }

            void putmatrix();

            friend void add(matrix,matrix);

};

void matrix::putmatrix()

{

            int i,j;

            for(i=0; i<3; i++)

            {

                        for(j=0; j<3; j++)

                                    cout<<a[i][j]<<" ";

                        cout<<endl;

            }

}

void add(matrix m1,matrix m2)

{

            int i,j;

            for(i=0; i<3; i++)

            {

                        for(j=0; j<3; j++)

                                    cout<<m1.a[i][j]+m2.a[i][j]<<" ";

                        cout<<endl;

            }

}

int main()

{

            matrix obj1;

            matrix obj2(obj1);

            cout<<"Matrix 1 (and Matrix 2 also):\n";

            obj1.putmatrix();

            cout<<"SUM of the Matrices:\n";

            add(obj1,obj2);

}