Thread: How do I find product of the matrices?

Hi

I'm trying to learn to find the product of two matrices using arrays. Please help me. I'm really stuck. And please don't introduce those topics which I won't be able to understand (I'm a beginner). In other words, please keep it simple. Thanks.

Code:

// product_of_two_matrices_1x3_and_3x1.cpp
// read two matrices and find product

#include <iostream>
#include <cstdlib>

using namespace std;

int main()
{
        float m1[1][3];
        float m2[3][1];
        float m3[1][3];
        int r, c;

        cout << "Enter matrix #1 below\n\n";

        for ( r=0; r<1; r++)
        {
                for (c=0; c<3 ; c++)
                {
                        cout << "enter entry for row #" << (r+1) << " and column"
                             << " #" << (c+1) << ": ";
                        cin >> m1[r][c];
                }
        }

        cout << "\n\nEnter matrix #2 below\n\n";

        for ( r=0; r<3; r++)
        {
                for (c=0; c<1; c++)
                {
                        cout << "enter entry for row #" << (r+1) << " and column"
                             << " #" << (c+1) << ": ";
                        cin >> m2[r][c];
                }
        }

        cout << "\n\nproduct of matrix #1 and matrix #2 is given below\n\n";

        //How do I find product of the matrices?

        return 0;

}

Originally Posted by tabstop

Do you know how to multiply matrices on paper?

Yes.

Code:

#include<iostream.h>

void input(int t[][3]);

void product(int a[][3], int b[][3], int c[][3]);

void display(int [][3]);

void main()

{

	 int a[3][3], b[3][3], c[3][3];

	 cout << "\tPROGRAM OF PRODUCT OF TWO 3X3 MATRICES\n\nEnter 9 Values for 3x3 Matrix 1 \n";

	 input(a);

	 cout << "Enter 9 Values for 3x3 Matrix 2 \n";

	 input(b);

	 product(a,b,c);

	 cout << "\nProduct of two matrices are \n\n";

	 display(c);

}

void input(int t[][3])

{

	 int i, j;

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

	 {

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

				cin >> t[i][j];

	 }


}

void product(int a[][3], int b[][3], int c[][3])

{

	 int i, j, k;

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

	 {

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

		  {

				c[i][j]=0;

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

				{

					 c[i][j] += + a[i][k] * b[k][j];

				}

		  }

	 }

}

void display(int c[][3])

{

	 int i, j;

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

	 {

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

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

    cout << "\n";

	 }

}

This is program for multiplying 3x3 matrices.......hope it will help u a lot

Thanks a lot, Jasir Ali.