This is a java program for Matrix Multiplication. To understand how it works, you should first know how matrix multiplication is done mathematically.
import java.util.Scanner;
public class MatrixMult{
public static void main(String[] args)
{
int[][] m1=new int[10][10];
int[][] m2=new int[10][10];
int[][] prod=new int[10][10];
int i,j,k,r1,c1,r2,c2;
Scanner sc=new Scanner(System.in);
System.out.println("Enter number of rows and columns of first matrix:");
r1=sc.nextInt();
c1=sc.nextInt();
System.out.println("Enter number of rows and columns of second matrix:");
r2=sc.nextInt();
c2=sc.nextInt();
if(r2==c1)
{
System.out.println("Enter elements of First matrix (row wise):");
for(i=0;i<r1;i++)
for(j=0;j<c1;j++)
m1[i][j]=sc.nextInt();
System.out.println("Matrix1 is :");
for(i=0;i<r1;i++)
{
for(j=0;j<c1;j++)
System.out.printf("%d ",m1[i][j]);
System.out.printf("\n");
}
System.out.println("Enter elements of Second matrix (row wise):");
for(i=0;i<r2;i++)
for(j=0;j<c2;j++)
m2[i][j]=sc.nextInt();
System.out.println("Matrix2 is:");
for(i=0;i<r2;i++)
{
for(j=0;j<c2;j++)
System.out.printf("%d ",m2[i][j]);
System.out.printf("\n");
}
System.out.println("Product of the Matrices (M1 x M2):");
for(i=0;i<r1;i++)
{
for(j=0;j<c2;j++)
{
prod[i][j]=0;
for(k=0;k<r1;k++)
prod[i][j]+=m1[i][k]*m2[k][j];
System.out.printf("%d ",prod[i][j]);
}
System.out.print("\n");
}
}
else
{
System.out.println("Matrices can't be multiplied.");
System.out.print("No. of columns of first matrix and no of rows of second are different.");
}
}
}
Output
Enter number of rows and columns of first matrix:
2
2
Enter number of rows and columns of second matrix:
2
2
Enter elements of First matrix (row wise):
5
8
6
4
Matrix1 is :
5 8
6 4
Enter elements of Second matrix (row wise):
5
6
8
9
Matrix2 is:
5 6
8 9
Product of the Matrices (M1 x M2):
89 102
62 72