C++ Programming Code Examples
C++ > Algorithms Code Examples
A C++ Program to Multiply two Matrices. Divide And Conquer Algorithm
/* A C++ Program to Multiply two Matrices. Divide And Conquer Algorithm */
# include <iostream.h>
# include <stdlib.h>
# include <conio.h>
class Matrix
{
private:
float matrix_a[3][3];
float matrix_b[3][3];
float matrix_c[3][3];
public:
Matrix( );
void get_matrix_a( );
void get_matrix_b( );
void multiply_matrices( );
void show_result_Matrix( );
};
Matrix::Matrix( )
{
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
matrix_a[i][j]=0;
matrix_b[i][j]=0;
matrix_c[i][j]=0;
}
}
gotoxy(1,1);
cout<<"*********************************************"<<endl;
cout<<" * * * * * * * * * * * * * * Matrix Multiplication * * * * ** * * * * * * *"<<endl;
cout<<"********************************************"<<endl;
gotoxy(1,25);
cout<<"*****************************************************";
}
void Matrix::get_matrix_a( )
{
gotoxy(1,6);
cout<<" Enter the values of the Matrix A row by row :
"<<endl;
cout<<" Ú ¿"<<endl;
cout<<" ³ ³"<<endl;
cout<<" ³ ³"<<endl;
cout<<" ³ ³"<<endl;
cout<<" À Ù"<<endl;
gotoxy(18,10);
cout<<" A = "<<endl;
int x=28;
int y=9;
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
gotoxy(x,y);
cin>>matrix_a[i][j];
x+=5;
}
x=28;
y++;
}
}
void Matrix::get_matrix_b( )
{
gotoxy(1,15);
cout<<" Enter the values of the Matrix B row by row :
"<<endl;
cout<<" Ú ¿"<<endl;
cout<<" ³ ³"<<endl;
cout<<" ³ ³"<<endl;
cout<<" ³ ³"<<endl;
cout<<" À Ù"<<endl;
gotoxy(18,19);
cout<<" B = "<<endl;
int x=28;
int y=18;
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
gotoxy(x,y);
cin>>matrix_b[i][j];
x+=5;
}
x=28;
y++;
}
}
void Matrix::multiply_matrices( )
{
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
float value=0;
float sum=0;
for(int k=0;k<3;k++)
{
value=matrix_a[j][k]*matrix_b[k][j];
sum+=value;
}
matrix_c[i][j]=sum;
}
}
}
void Matrix::show_result_Matrix( )
{
clrscr( );
gotoxy(1,1);
cout<<"*********************************************************"<<endl;
cout<<" * * * * * * * * * * * * * * Matrix Multiplication * * * * ** * * * * * * *"<<endl;
cout<<"*************************************************************"<<endl;
gotoxy(1,6);
cout<<" The values of Matrix A and B are :"<<endl;
cout<<" Ú ¿ Ú
¿"<<endl;
cout<<" ³ ³ ³
³"<<endl;
cout<<" ³ ³ ³
³"<<endl;
cout<<" ³ ³ ³
³"<<endl;
cout<<" À Ù À Ù"<<endl;
gotoxy(45,9);
cout<<" B = "<<endl;
gotoxy(10,9);
cout<<" A = "<<endl;
gotoxy(1,15);
cout<<" The Product of Matrix A and B is :
"<<endl;
cout<<" Ú ¿"<<endl;
cout<<" ³ ³"<<endl;
cout<<" ³ ³"<<endl;
cout<<" ³ ³"<<endl;
cout<<" À Ù"<<endl;
gotoxy(13,19);
cout<<" A * B = "<<endl;
int x_1=20;
int y_1=8;
int x_2=55;
int y_2=8;
int x_3=28;
int y_3=18;
for(int i=0;i<3;i++)
{
for(int j=0;j<3;j++)
{
gotoxy(x_1,y_1);
cout<<matrix_a[i][j];
gotoxy(x_2,y_2);
cout<<matrix_b[i][j];
gotoxy(x_3,y_3);
cout<<matrix_c[i][j];
x_1+=5;
x_2+=5;
x_3+=5;
}
x_1=20;
y_1++;
x_2=55;
y_2++;
x_3=28;
y_3++;
}
gotoxy(1,25);
cout<<"*********************************************";
}
int main( )
{
textmode(BW80);
clrscr( );
Matrix Obj;
Obj.get_matrix_a( );
Obj.get_matrix_b( );
Obj.multiply_matrices( );
Obj.show_result_Matrix( );
getch( );
return 0;
}
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