Matrix Multiplication
Algorithm
Input: Input rows and column of the first and second matrices, elements of the matrices
output: Displays the multiplication of element of the matrices
- Start
- Input the number of row and column of 1st matrix and store it in m1, n1
- Input the number of row and column of 2nt matrix and store it in m2, n2
- if n1 != m2
4.1 Print "Matrix multiplication not possible" - else
5.1 Input the elements of matrix 1 and matrix 2 say a [m1] [n1] and b [m2] [n2]
5.2 Print "The multiplication of matrix 1 and 2 is "
5.3 for i = 0 to m1
5.3.1 for j = 0 to n2
5.3.1.1 c [ i ] [ j ] = 0
5.3.1.2 for k = 0 to n1
5.3.1.2.1 c [ i ] [ j ] = c [ i ] [ j ] + a [ i ] [ k ] * b [ k ] [ j ] - print the matrix c
- Stop
Java Program
import java.util.Scanner;
public class Main {
public static void main(String args[]) {
int m1,n1,m2,n2;
Scanner reader = new Scanner(System.in);
System.out.printf("Enter the number of rows of first matrix:");
m1=reader.nextInt( );
System.out.printf("Enter the number of coloumns of first matrix:");
n1=reader.nextInt( );
System.out.printf("Enter the number of rows of second matrix:");
m2=reader.nextInt( );
System.out.printf("Enter the number of coloumns of second matrix:");
n2=reader.nextInt( );
int a[ ] [ ] = new int [m1] [n1];
int b[ ] [ ] = new int [m2] [n2];
int c[ ] [ ] = new int [m1] [n2];
if(n1!=m2) {
System.out.printf("Matrix multiplication not possible");
}
else {
System.out.println("Enter the elements of first matrix:");
for(int i=0;i<m1;i++) {
for(int j=0;j<n1;j++) {
a [ i ] [ j ] = reader.nextInt( );
}
}
System.out.println("Enter the elements of second matrix:");
for(int i=0;i<m2;i++) {
for(int j=0;j<n2;j++) {
b [ i ] [ j ] = reader.nextInt( );
}
}
for(int i=0;i<m1;i++) {
for(int j=0;j<n2;j++) {
c [ i ] [ j ] = 0;
for(int k=0;k<n1;k++) {
c [ i ] [ j ] = c [ i ] [ j ] + ( a [ i ] [ k ] * b [ k ] [ j ] );
}
}
}
System.out.println("The multiplied matrix is:");
for(int i=0;i<m1;i++) {
for(int j=0;j<n2;j++) {
System.out.printf(c [ i ] [ j ] + "\t");
}
System.out.println();
}
}
}
}
Output
Enter the number of rows of the first matrix: 2
Enter the number of columns of the first matrix: 2
Enter the number of rows of the second matrix: 2
Enter the number of columns of the second matrix: 2
Enter the elements of the first matrix:
1
2
3
4
Enter the elements of the second matrix:
1
2
3
4
The matrix multiplication is
7 22
7 22
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