Java Program to subtract two matrices

Program

import java.util.Scanner;
class SubtractMatrix
{
    public static void main(String[] args) {
        int i, j;
        int row, col;
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter the number of rows for both matrix:\t");
        row = sc.nextInt();
        System.out.println("Enter the number of columns for both matrix:\t");
        col = sc.nextInt();
        int mat1[][] = new int[row][col];
        int mat2[][] = new int[row][col];
        int mat3[][] = new int[row][col];
        System.out.printf("Enter %d elements for matrix 1\n", row * col);
        for (i = 0; i < row; i++)
        {
            for (j = 0; j < col; j++)
            {
                mat1[i][j] = sc.nextInt();
            }
        }
        System.out.printf("Enter %d elements for matrix 2\n", row * col);
        for (i = 0; i < row; i++)
        {
            for (j = 0; j < col; j++)
            {
                mat2[i][j] = sc.nextInt();
            }
        }
        for (i = 0; i < row; i++)
        {
            for (j = 0; j < col; j++)
            {
                mat3[i][j] = mat1[i][j] - mat2[i][j];
            }
        }
        System.out.println("The Subtract of two Matrices is:\n");
        for (i = 0; i < row; i++)
        {
            for (j = 0; j < col; j++)
            {
                System.out.printf("%d\t", mat3[i][j]);
            }
            System.out.println("\n");
        }
    }
}

This program subtracts two matrices of the same dimensions and displays the result. Below is a step-by-step explanation:

1. User Input for Matrix Dimensions

• The program prompts the user to enter:
  • The number of rows (row).
  • The number of columns (col).
• Both matrices must have the same dimensions.

2. Matrix Declaration

• Three 2D arrays are declared:
  • mat1[][] → Stores the first matrix.
  • mat2[][] → Stores the second matrix.
  • mat3[][] → Stores the resultant matrix (subtraction result).

3. Taking Input for Both Matrices

• The user is prompted to enter elements for both matrices.
• Nested loops are used to iterate through the rows (i) and columns (j) of the matrices.

4. Matrix Subtraction Logic

Each element of mat3[][] is calculated as:

[ mat3[i][j] = mat1[i][j] - mat2[i][j] ]

• The program iterates through each element using nested loops.
• It subtracts corresponding elements of mat1[][] and mat2[][] and stores the result in mat3[][].

5. Displaying the Resultant Matrix

• The final subtracted matrix (mat3[][]) is printed in a formatted manner using System.out.printf().

Example Execution

Input

Enter the number of rows for both matrices: 2
Enter the number of columns for both matrices: 3
Enter 6 elements for matrix 1:
5 8 3
2 7 6
Enter 6 elements for matrix 2:
1 4 2
3 5 4

Matrix Subtraction

The Subtract of two Matrices is:
4   4   1
-1  2   2

Key Points

• Handles matrices of any valid dimensions
• Ensures both matrices have the same dimensions
• Uses nested loops for input, processing, and output
• Displays formatted output for readability

Output

$ javac SubtractMatrix.java
$ java SubtractMatrix
Enter the number of rows for both matrix:
3
Enter the number of columns for both matrix:
3
Enter 9 elements for matrix 1
34
22
12
86
74
32
45
65
71
Enter 9 elements for matrix 2
99
15
78
85
36
63
45
58
11
The Subtract of two Matrices is:
-65     7       -66
1       38      -31
0       7       60