Functional decomposition

A quadratic equation is an algebraic equation of degree two. It's easy to solve this equation when you know the quadratic formula.

Here is a simple program for calculating the real roots of a quadratic equation:

public static void findRoots(double a, double b, double c) {
    // the equation is ax^2 + bx + c = 0
    double discriminant = b * b - 4 * a * c;
    if (discriminant < 0) {
        System.out.println("No real roots!");
    } else if (discriminant == 0) {
        double x = -b / (2 * a);
        System.out.println("x = " + x);
    } else {
        double x1 = (-b + Math.pow(discriminant, 0.5)) / (2 * a);
        double x2 = (-b - Math.pow(discriminant, 0.5)) / (2 * a);
        System.out.println("x1 = " + x1);
        System.out.println("x2 = " + x2);
    }
}

What if we change it a bit by decomposing this code and creating additional methods? That's what we get then:

public static double calculateDiscriminant(double a, double b, double c) {
    return b * b - 4 * a * c;
}

public static void calculateRoots(double a, double b, double c, double discriminant) {
    double x1 = (-b + Math.pow(discriminant, 0.5)) / (2 * a);
    double x2 = (-b - Math.pow(discriminant, 0.5)) / (2 * a);
    if (x1 == x2) {
        System.out.println("x = " + x1);
    } else {
        System.out.println("x1 = " + x1);
        System.out.println("x2 = " + x2);
    }
}

What should the main method look like after decomposition?

Make sure that the method produces the correct output and is properly decomposed (no unnecessary actions are performed).

Choose the option:

1)

public static void main(String[] args) {

    Scanner scanner = new Scanner(System.in);
    int a = scanner.nextInt();
    int b = scanner.nextInt();
    int c = scanner.nextInt();

    double discriminant = calculateDiscriminant(a, b, c);

    if (discriminant < 0) {
        System.out.println("No real roots!");
    } else if (discriminant == 0) {
        calculateRoots(a, b, c, discriminant);
    } else {
        calculateRoots(a, b, c, discriminant);
    }
}

2)

public static void main(String[] args) {

    Scanner scanner = new Scanner(System.in);
    int a = scanner.nextInt();
    int b = scanner.nextInt();
    int c = scanner.nextInt();

    double discriminant = calculateDiscriminant(a, b, c);

    calculateRoots(a, b, c, discriminant);
}

3)

public static void main(String[] args) {
    
    Scanner scanner = new Scanner(System.in);
    int a = scanner.nextInt();
    int b = scanner.nextInt();
    int c = scanner.nextInt();

    double discriminant = calculateDiscriminant(a, b, c);

    if (discriminant < 0) {
        System.out.println("No real roots!");
    } else {
        calculateRoots(a, b, c, discriminant);
    }
}