MatrixInverse

import java.util.Scanner;

public class MatrixInverse {
    static double[][] A = new double[3][3];
    static double a = 0;
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("Enter a11, a12, a13, a21, a22, a23, a31, a32, a33:");
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                A[i][j] = input.nextDouble();
            }
        }
        MatrixInverse.a = A[0][0]*A[1][1]*A[2][2] + A[2][0]*A[0][1]*A[1][2] + A[0][2]*A[1][0]*A[2][1]
                - A[0][2]*A[1][1]*A[2][0] - A[0][0]*A[1][2]*A[2][1] - A[2][2]*A[1][0]*A[0][1];
        input.close();
        double ainv[][] = inverse(A);
        if (a == 0)
            System.out.println("No inverse matrix");
        else {
            for (int i = 0; i < 3; i++) {
                for (int j = 0; j < 3; j++) {
                    System.out.print(ainv[i][j] + " ");
                }
                System.out.print("\n");
            }
        }
    }
    public static double[][] inverse(double[][] A) {
        double[][] inverse = {{(A[1][1]*A[2][2] - A[1][2]*A[2][1])/a, (A[0][2]*A[2][1] - A[0][1]*A[2][2])/a, (A[0][1]*A[1][2] - A[0][2]*A[1][1])/a},
                {(A[1][2]*A[2][0] - A[1][0]*A[2][2])/a, (A[0][0]*A[2][2] - A[0][2]*A[2][0])/a, (A[0][2]*A[1][0] - A[0][0]*A[1][2])/a},
                {(A[1][0]*A[2][1] - A[1][1]*A[2][0])/a, (A[0][1]*A[2][0] - A[0][0]*A[2][1])/a, (A[0][0]*A[1][1] - A[0][1]*A[1][0])/a}};
        return inverse;
    }
}