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Matrix multiplication is a binary operation and it produces a matrix from two or more matrices. But for matrix multiplication, the number of columns of the first matrix should be equal to the number of rows of the 2nd matrix.

Let the matrices be:

Where A and B are two given matrices which is to be multiplied and C is the resultant matrix where the result of the matrix multiplication. 

The number of rows of C will be equal to the number of rows of the 1st matrix and the number of columns of the matrix C will be equal to the number of columns of the 2nd matrix.

For this example, A is a 2×2 matrix, B is also a 2×2 matrix, and therefore, the resultant matrix C is also a 2×2 matrix. So, we will need 4 steps to get the result.

Step 1:

Step 2: 

Step 3: 

Step 4:

So, the matrix:

INPUT: Two matrices
OUTPUT: The resultant matrix after multiplication.

PROCESS:
Step 1: [Taking the inputs]
	Read r1, c1 [The number of rows and columns of the first matrix]
	Read r2, c2 [The number of rows and columns of the second matrix]
	If c1≠r2 then
		Print "The matrix multiplication is not possible"
return
	[End of ‘if’]
Print "Enter first matrix......"
For i=0 to r1-1 repeat
      		For j=0 to c1-1 repeat
			Read a[i][j]
     		[End of ‘for’ loop]
  	[End of ‘for’ loop]
Print "Enter second matrix......."
  	For i=0 to r2-1 repeat
    		For j=0 to c2-1 repeat
			Read b[i][j]
     		[End of ‘for’ loop]
  	[End of ‘for’ loop]
	For i=0 to r1-1 repeat
    		For j=0 c2-1 repeat
			Set c[i][j]<-0
		[End of ‘for’ loop]
	[End of ‘for’ loop]
  	Call the function multiply(a,r1, c1, b,r2, c2, c)
Step 2: [Function ‘multiply(a,r1, c1, b,r2, c2, c)’]
Set i <- 0, j <- 0, k <- 0
 	if i ≥ r1 then
        		return
    	else if i < r1 then
        		if j < c2 then
            			if k < c1 then
                			Set c[i][j]<-c[i][j] + a[i][k] * b[k][j]
                			Set k<-k+1
                			Call multiply(a,r1, c1, b,r2, c2, c)
            			[End of ‘if’]
            			Set k <- 0
            			Set j<-j+1
           			Call multiply(a,r1, c1, b,r2, c2, c);
        		[End of ‘if’]
        		Set j <- 0
        		Set i<-i+1
        		Call multiply(a,r1, c1, b,r2, c2, c);
    	[End of ‘if’]
[End of function ‘multiply(a,r1, c1, b,r2, c2, c)’]
Step 3: Stop.