Question 4.5: Write a program in Java to calculate determinant of a 3 x 3 matrix.
Test Data :
Input elements in the first matrix :
element - [0],[0] : 1
element - [0],[1] : 0
element - [0],[2] : -1
element - [1],[0] : 0
element - [1],[1] : 0
element - [1],[2] : 1
element - [2],[0] : -1
element - [2],[1] : -1
element - [2],[2] : 0
Expected Output :
The matrix is :
1 0 -1
0 0 1
-1 -1 0
The Determinant of the matrix is: 1
Solution:
package lab4problem5;
import java.util.Scanner;
public class Lab4Problem5 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Input elements in the first matrix :");
int matrix[][] = new int[3][3];
for(int i = 0; i < 3; i++){
for (int j = 0; j < 3; j++) {
System.out.print("element - [" + i + "],[" + j + "] :");
matrix[i][j] = input.nextInt();
}
}
for(int i = 0; i < 3; i++){
for (int j = 0; j < 3; j++) {
System.out.print(matrix[i][j]+" ");
}
System.out.println();
}
int sum = 0;
sum = (matrix[0][0] * ((matrix[1][1] * matrix[2][2]) - (matrix[1][2] * matrix[2][1])))
+ (matrix[0][1] * ((matrix[1][0] * matrix[2][2]) - (matrix[1][2] * matrix[2][0]))) +
(matrix[0][2] * ((matrix[1][0] * matrix[2][1]) - (matrix[1][1] * matrix[2][0])));
System.out.println("The Determinant of the matrix is: "+ sum);
}
}
