Answer:
// Matrix.java
// package
import java.util.*;
// class definition
class Matrix
{
// main method of the class
public static void main (String[] args) throws java.lang.Exception
{
try{
// object to read the input
Scanner scr=new Scanner(System.in);
// object to generate random Number
Random rand = new Random();
// Part 1
// variable
int n;
System.out.print("Enter the size of square matrix:");
// read the size of matrix
n=scr.nextInt();
// check size is less than 4
while(n<4)
{
System.out.println("Size of array must be greater or equal to 4:");
// ask again to enter the size
// Part 2
System.out.print("Enter the size again:");
// read the size again
n=scr.nextInt();
}
// matrix of size n
int arr1[][]=new int[n][n];
int arr2[][]=new int[n][n];
int arr3[][]=new int[n][n];
//part 3
//fill the matrix with Random Number
for(int x=0;x<n;x++)
{
for(int y=0;y<n;y++)
{
arr1[x][y]=rand.nextInt(10);
}
}
for(int x=0;x<n;x++)
{
for(int y=0;y<n;y++)
{
arr2[x][y]=rand.nextInt(10);
}
}
// part 4
// print the matrix Elements
System.out.println("Elements of the first array:");
for(int x=0;x<n;x++)
{
for(int y=0;y<n;y++)
{
System.out.print(arr1[x][y]+" ");
}
System.out.println();
}
System.out.println("Elements of the second array:");
for(int x=0;x<n;x++)
{
for(int y=0;y<n;y++)
{
System.out.print(arr2[x][y]+" ");
}
System.out.println();
}
// part 4
// matrix multiplication and print Elements
System.out.println("Array after multiplication:");
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
arr3[i][j]=0;
for(int k=0;k<n;k++)
{
arr3[i][j]+=arr1[i][k]*arr2[k][j];
}
System.out.print(arr3[i][j]+" ");
}
System.out.println();
}
}catch(Exception ex){
return;}
}
}
Explanation:
In part 1, ask user to enter the size of square matrix.check the size is
less than 4 or not.In part 2, if the size is less than 4 then ask again to
enter the size.In part 3, fill the matrix with random numbers.In part 4,
print both the matrix elements.In part 5, perform matrix multiplication and
store the elements in third matrix.Then print the matrix elements of third
matrix.
Output:
Enter the size of square matrix:3
Size of array must be greater or equal to 4:
Enter the size again:4
Elements of the first array:
2 8 0 8
8 6 5 2
6 7 6 7
8 1 0 8
Elements of the second array:
2 1 6 0
1 4 8 6
6 4 1 6
6 3 6 9
Array after multiplication:
60 58 124 120
64 58 113 84
97 79 140 141
65 36 104 78
