public class testing_programm {
    public static double epsilon = Math.pow(10,-3);
    public static void main(String[] args) {
        double x0[];
        double x[] = {0,0,0};
        double y[] = {-0.6, 0.868, 0.03};
        double matrix[][] = {
                {0.5, 0.08, -0.04},
                {0.1, 0.5, -0.212},
                {-0.069, -0.29, 0.5}
        };
        int count = 0;
        do {
            x0 = x;
            x = mul(matrix,x0);
            for(int i = 0; i < x.length; i++) {
                x[i] += y[i];
            }
            count++;
        }   while (check(x,x0));
        System.out.println("Vector:");
        for(int i = 0; i < x.length; i++) {
            System.out.println(x[i]);
        }
        System.out.println("Amount of iterations = " + count + ";");
    }
    public static double[] mul (double[][] m, double[] v) {
        double vector[] = new double[v.length];
        for(int i = 0; i < v.length; i++){
            for(int j = 0; j < m.length; j++) {
                vector[i] += m[i][j] * v[j];
            }
        }
        return vector;
    }
    public static boolean check (double[] x1, double[] x2) {
        double max = Math.abs(x1[0] - x2[0]);
        for(int i = 1; i < x1.length; i++) {
            if(Math.abs(x2[i] - x1[i]) > max) {
                max = Math.abs(x2[i] - x1[i]);
            }
        }
        if(max < epsilon) {
            return false;
        }
        return true;
    }
}