SGST , CGST & IGST dependancies

GST.java

import javax.swing.*;

public class GST {
    JFrame f;

    public void main(double b, char a, double c) {
        f = new JFrame();
        switch (a) {
            case 'a' -> {
                JOptionPane.showMessageDialog(f, "SGST = " + c + "% , CGST = " + c + "%");
                JOptionPane.showMessageDialog(f, "SGST = Rs." + Math.round((((c * b) / 100))) + "\n CGST = Rs." + Math.round((((c * b) / 100))));
                JOptionPane.showMessageDialog(f, "Final cost = Rs." + Math.round((b + ((2 * c * b) / 100))));
            }
            case 'b' -> {
                JOptionPane.showMessageDialog(f, "IGST = " + c + "%");
                JOptionPane.showMessageDialog(f, "Final cost = Rs." + Math.round((b + ((c * b) / 100))));
            }
        }
    }
}