Java Code for Matrix Subtraction

To subtract two matrices (A and B) in Java, they must have the same dimensions, meaning the same number of rows and columns. It is not possible to subtract a 2 × 3 matrix from a 3 × 2 matrix, as the dimensions do not match. To perform matrix subtraction, we subtract the corresponding elements of the matrices.

(A - B)<sub>ij</sub>= A<sub>ij</sub> - B<sub>ij</sub>

To subtract two matrices, we can iterate through each element of the first and second matrices. By calculating the difference between their corresponding elements, we can store the result in a third matrix. This process involves looping through the matrices and performing element-wise subtraction.

Algorithm for Matrix Subtraction in Java

• • STEP 1: START
  • STEP 2: DEFINE rows, cols
  • STEP 3: INITIALIZE first matrix a[][] ={{4,5,6},{3,4,1}, {1,2,3}}
  • STEP 4: INITIALIZE second matrix b[][] ={{2,0,3}, {2,3,1}{1,1,1}}
  • STEP 5: rows = a.length
  • STEP 6: cols = a[0].length
  • STEP 7: DEFINE diff[][]
  • STEP 8: REPEAT STEP 9 to STEP 10 UNTIL i<rows
    //for(i=0;i<rows; i++)
  • STEP 9: REPEAT STEP 10 UNTIL j<cols
    //for(j=0;j<cols; j++)
  • STEP 10: diff[i][j] =a[i][j] – b[i][j]
  • STEP 11: PRINT “Subtraction of two matrices:”
  • STEP 12: REPEAT STEP 13 to STEP 14 UNTIL i<rows
    //for(i=0;i<rows; i++)
  • STEP 13: REPEAT STEP 14 UNTIL j<cols
    //for(j=0; j<cols; j++)
  • STEP 13: PRINT diff[i][j]
  • STEP 14: PRINT new line
  • STEP 15: END

Java Code for Matrix Subtraction

public class Sub_Matrix  
{  
    public static void main(String[] args) {  
        int rows, cols;  
  
        //Initialize matrix a  
          int a[][] = {  
                          {4, 5, 6},  
                          {3, 4, 1},  
                          {1, 2, 3}  
                       };  
  
          //Initialize matrix b  
          int b[][] = {  
                          {2, 0, 3},  
                         {2, 3, 1},  
                         {1, 1, 1}  
                     };  
  
          //Calculates number of rows and columns present in given matrix  
          rows = a.length;  
        cols = a[0].length;  
  
          //Array diff will hold the result  
        int diff[][] = new int[rows][cols];  
  
        //Performs subtraction of matrices a and b. Store the result in matrix diff  
        for(int i = 0; i < rows; i++){  
            for(int j = 0; j < cols; j++){  
                diff[i][j] = a[i][j] - b[i][j];  
            }  
        }  
  
        System.out.println("Subtraction of two matrices: ");  
        for(int i = 0; i < rows; i++){  
            for(int j = 0; j < cols; j++){  
               System.out.print(diff[i][j] + " ");  
            }  
            System.out.println();  
        }  
    }  
}

Output:

Subtraction of two matrices:
1    5    3
1    1    0
0    1    2