Question

Write a C program to implement matrix multiplication operations. First, you need to prompt the user for the size of both matrix. Then take inputs for both matrices and perform matrix multiplication operation. Finally, print the resulting matrix into the output.

Answer 1

Program:

#include<stdio.h>

int main()
{
   int matrix1[20][20], matrix2[20][20], resultantMatrix[20][20],result=0;
   int row1,column1,row2,column2;
   int i=0,j=0,k=0;
  
   int repeat=1;
  
   //prompt and read number of rows and columns for the matrices until correct order is entered
   do
   {
       //read the size of matrix 1
       printf("\nEnter size of matrix1 (rows columns) : ");
       scanf("%d%d",&row1,&column1);
      
       //read the size of matrix 2
       printf("\nEnter size of matrix2 (rows columns) : ");
       scanf("%d%d",&row2,&column2);
      
       //check if mauliplication is possible or not
       if(column1!=row2)
       {
           //if number of columns in matrix 1 is not equal to number of rows in matrix 2
           //multiplication is not possible prompt again
           printf("\nThe matrices of the given size cannot be multiplied. Try again...\n");
           repeat=1;
       }
       else
       {
           repeat=0;
       }
   }while(repeat);

   //read the matrix 1
   printf("\nEnter matrix-1: \n");
   for(i=0;i<row1;i++)
   {
       for(j=0;j<column1;j++)
       {
           printf("\nEnter element for row %d X column %d :",(i+1),(j+1));
           scanf("%d", &matrix1[i][j]);
       }
   }
  
   //read the matrix 2
   printf("\nEnter matrix-2: \n");
   for(i=0;i<row2;i++)
   {
       for(j=0;j<column2;j++)
       {
           printf("\nEnter element for row %d X column %d :",(i+1),(j+1));
           scanf("%d", &matrix2[i][j]);
       }
   }
  
   //multiply the two matrices and store the values in resultant matrix
   for(i=0;i<row1;i++)
   {
       for(j=0;j<column2;j++)
       {
           for(k=0;k<row2;k++)
           {
               //row value * column value
               result=result+matrix1[i][k]*matrix2[k][j];
           }
          
           //assign value in resultantMatrix
           resultantMatrix[i][j]=result;
           result=0;
       }
   }
  
   //clear the screen, can remove if not necessary
   system("cls");
   printf("\nMatrix-1 is:\n");
  
   //print matrix 1
   for (i=0;i<row1;i++)
   {
   for (j=0; j<column1;j++)
    {
        printf("%d\t", matrix1[i][j]);
       }
   printf("\n");
}
  
//print matrix 2
printf("\nMatrix-2 is:\n");
   for (i=0;i<row2;i++)
   {
   for (j=0;j<column2;j++)
    {
        printf("%d\t", matrix2[i][j]);
       }
   printf("\n");
}
  
//print the resultant matrix
printf("\nResultant Matrix is:\n");
   for (i=0;i<row1;i++)
   {
   for (j=0;j<column2;j++)
    {
        printf("%d\t", resultantMatrix[i][j]);
       }
   printf("\n");
}
   return 0;
}

Output:

C:Users\Vickyl\Desktop DevC++Programs MatrixMultiplication.exe Enter size of matrixi1 <rows columns : 2 2 Enter size of matrix2 <rows columns 2 2 Enter matrix-1: Enter element for rOw 1 R column 1 :1 Enter element for row 1 R column 2 2 Enterelement for Enter element for row 2 R column 2 4 Enter matrix-2: Enter element for row 1 R column 1 :5 Enterelement for Enter element for row 2 R column 1 7 Enterelement for row 2 X column 1 :3 row 1 X column 2 :6 row 2 X column 2 :8

CAUsers Vicky Desktop\DevC++Programs MatrixMultiplication.exe Matrix-1 is: 3 2 4 Matrix-2 is: 5 7 6 8 Resultant Matrix is: 19 43 50 Process exited after 34.07 seconds with return value 0 Press any key to continue . . .

CAUsers\VickyDesktopDevC++Programs\MatrixMultiplication.exe (rows colunns> : 2 3 Enter size of matrix! Enter size of matrix2 Cows columns) 3 2 Enter matrix-1: Enter element for Enter element for row 1 R column 2 2 Enter element for Ow 1 R column 3 :3 Enter element for row 2 R column 1 4 Enter element for ro 2 column 2 :5 Enter element for ro 2 R column 3 6 Enter matrix-2 Enterelement for rOw 1 R column 1 :7 Enter element for row 1 X column 2 :8 Enterelement for Enter element for row 2 R column 2 :10 Enterelement for Enter element for row 3 R column 2 12 row 1 column 1 :1 row 2 column 1 :9 row 3 X column 1 :11

.. CAUsers\VickyDesktop\DevC++Programs\MatrixMultiplication.exe Matrix-1 is: 4 2 5 3 6 Matrix-2 is: 2 9 8 10 12 Resultant Matrix is: 58 139 64 154 Process exited after 42.5 seconds with return value 0 Press any key to continue .. .