0
true
false

7
-1
abXdeabXde
c
abcdeabcde

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class MoveSmiley extends JFrame {
    int currentIndex = 4;
    JButton[] buttons = new JButton[9];
    JButton leftButton = new JButton(new ImageIcon("left.gif"));
    JButton rightButton = new JButton(new ImageIcon("right.gif"));
    ImageIcon icon = new ImageIcon("smiley.gif");
    
    JPanel centerPanel = new JPanel(new GridLayout(1,0));
    JPanel southPanel = new JPanel(new GridLayout(1,0));
    
    int newIndex;
    
    public MoveSmiley() {
        super("Move smiley");
        for(int i = 0; i < 9; i++) {
            buttons[i] = new JButton(Integer.toString(i));
            buttons[i].setActionCommand(Integer.toString(i));
            centerPanel.add(buttons[i]);
            buttons[i].addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    newIndex = Integer.parseInt(e.getActionCommand()); 
                    setIndex(newIndex);
                }
            });
        }
        buttons[4].setText("");
        buttons[4].setIcon(icon);
        
        southPanel.add(leftButton);
        southPanel.add(rightButton);
        
        // use seperate classes for left button action and right button action
        leftButton.addActionListener(new Listener(this, "left"));
        rightButton.addActionListener(new Listener(this, "right"));
        
        getContentPane().add(centerPanel);
        getContentPane().add(southPanel, BorderLayout.SOUTH);
    }
    
    public void setIndex(int newIndex) {
        buttons[currentIndex].setIcon(null);
        buttons[currentIndex].setText(Integer.toString(currentIndex));
        buttons[newIndex].setText("");
        buttons[newIndex].setIcon(icon);
        currentIndex = newIndex;       
    }
    
    public static void main(String[] args) {
        MoveSmiley f = new MoveSmiley();       
        f.setSize(450,100);
        f.setVisible(true);
    }
}


class Listener implements ActionListener {
    MoveSmiley smiley;
    String direction; // "left" or "right"
    
    public Listener(MoveSmiley smiley,  String direction) {
        this.direction = direction;
        this.smiley = smiley;
    }
    
    public void actionPerformed(ActionEvent e) {
        int index = smiley.currentIndex;
        if(direction.equals("left")) {
            if(index != 0) {
                smiley.setIndex(index-1);
            } 
        } else {
            if(index != 8) {
                smiley.setIndex(index+1);
            }
        }
    }
}

import java.io.*;

public class PhoneBill {
    public static void main(String[] args) {
        String filename = "bill.txt";
        BufferedReader in = null;
        try {
            in = new BufferedReader(new FileReader(filename));
        } catch (FileNotFoundException ex) {
            System.out.println("I can't process the file.");
            System.exit(0);
        }
        
        String line = null;
        String time=null;
        int min=0;
        int totalMin=0;
        int hr = 0;
        try {
            while((line = in.readLine())!=null) {
                String[] data = line.split(" # ");
                time = data[1];
                String[] hrmin = time.split(":");
                hr = Integer.parseInt(hrmin[0]);
                if(hr >= 8 && hr < 19) {
                    min = Integer.parseInt(data[3]);
                    //System.out.println(min);
                    totalMin+=min;
                }
            }                
        } catch (IOException ex) {
            System.out.println("I can't process the file.");
            System.exit(0);
        }
        
        System.out.println("You have to pay $ " + totalMin*0.25);
        
        try {
            in.close();
        } catch (IOException ex) {
        }
    }
}