/* Sirul lui Fibonacci - Programare dinamica
 */
import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class Fibonacci extends Applet implements ActionListener
{
    private TextField textA, textB, textN, textRez;
    private Label labelA, labelB, labelN, labelRez;
    private Button butonRez;

    public void init()
    {
        labelA = new Label("Primul element din sir:    a = ");
        add(labelA);

        textA = new TextField(3);
        add(textA);

        labelB = new Label("Al doilea element din sir: b = ");
        add(labelB);

        textB = new TextField(3);
        add(textB);

        labelN = new Label("Element de calculat n =         ");
        add(labelN);

        textN = new TextField(3);
        add(textN);

        Label l1 = new Label("                           ");
        add(l1);

        butonRez = new Button("Calculeaza Fibonacci(n)");
        add(butonRez);
        butonRez.addActionListener(this);

        Label l2 = new Label("                                         ");
        add(l2);

        labelRez = new Label("Fibonacci(n) =");
        add(labelRez);

        textRez = new TextField(11);
        add(textRez);
        textRez.setEditable(false);
    }

    private int fibonaci(int a, int b, int n)
    {
        int c = 0;

        for(int i = 2; i < n; i++)
        {
            c = a + b;
            a = b;
            b = c;
        }

        return c;
    }

    public void actionPerformed(ActionEvent e)
    {
        try
        {
            textRez.setText("" + fibonaci(Integer.parseInt(textA.getText()), Integer.parseInt(textB.getText()), Integer.parseInt(textN.getText())));
        }catch(NumberFormatException nfe)       {      return;       }
    }
}