1) 1 pt each
(a) C (b) E (c) D (d) (e) A

2 a)  4pts
Output 1:
x = 2
y = 3
Output 2:
x = 10
y = 5

b) 3pts)
Output1 : 3
Output2 : 3
Output3 : 8

c) 3 pts.

d) 6 pts)
(i) 10
(ii)
NumberFormatException
3
(iii)
ArrayIndexOutOfBoundsException
12

Q3)
3 pts for each. 1pt for error, 1pt for correction 1 pt for explanation.
(a) try catch in.read
(b) declare int a outside of try block
(c) type cast v.firstElement()
(d) implements mathod(String x)

Q4)
a)
boolean isPicture(File file) {
// Your codes
  String s = file.toString();
  return s.endsWith(".gif") || s.endsWith(".jpg");

}
b)
public class GraphicsTest extends javax.swing.JFrame {
    public void paint(java.awt.Graphics g) {
        java.awt.Color color = java.awt.Color.black;
        g.setColor(color); 
    }
}

5 a)
import java.util.*;

public class Person {
   public String lastName;
   public String firstName;
   public char gender;
   
   public Person(String lastName, String firstName, char gender) {
        this.lastName = lastName;
        this.firstName = firstName;
        this.gender = gender;
   }
   
  // total 5 pts
   public boolean equals(Object p) {
      //Your codes
      if(p instanceof Person) { // 1pt
          Person temp = (Person)p ; // 1pt
          return lastName.equals(temp.lastName) &&  //2 pts 
                 firstName.equals(temp.firstName);
          
      } else {
          return false; // 1pt
      }
      
   } 
   
   // total 6 pts
   public static Vector male(Vector v) {
       Vector result = new Vector(); // 1 pt for creating the vector
       for(int i = 0; i < v.size(); i++) { // 1 pt for the lop
           Person p = (Person)result.get(i); // 1pt for getting the i-th
           if(p.gender == 'm' || p.gender == 'M') { // 1 pt for testing
               result.add(p);                    // 1 pt for adding
           }
       }
       return result; // 1 pt for returning
   }       
   
   // total 4 pts
   public static int common(Vector v1, Vector v2) {
       int num = 0;
       for(int i = 0; i < v1.size(); i++) { // 1pt
           if(v2.contains(v1.get(i))) { // 3 pts
               num++;
           }
       }
       return num;
   }
}

import java.io.*;

// 2 pts for general impression, like compiler error, does the
// student's program make any sense at all? 
public class Search {
   public static boolean  search(File file, String keyword) {
       try {
           BufferedReader in = new BufferedReader(new FileReader(file)); // 1pt 
           String line = null;
           while((line = in.readLine()) != null) { // 1 pts for the loop
               if(line.indexOf(keyword) >= 0) { // 2 pts
                   return true;
               }
           }
           return false; // 1 pts 
       } catch (Exception ex) { // 2pts for catch exceptions and return
           return false;
       }
   }

   public static void main(String[] args) throws Exception {
       String folder = args[0];
       String keyword = args[1];
       // your codes
       File file = new File(args[0]); // 1 pt
       PrintStream out = new PrintStream(new FileOutputStream("out.txt")); // 1pt

       if(!file.exists()) { // 1 pt
           out.println("The folder doesn't exists.");
           return;
       }
       
       if(!file.isDirectory()) { // 1pt
           out.println("The folder is not a directory.");
           return;
       }
       
       // 4 pts 
       File[] list = file.listFiles(); 
       for(int i = 0; i < list.length; i++) {
           if(search(list[i], keyword)) {
               out.println(list[i]);
           }
       }
   }
}

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

public class GetMoney extends JFrame implements ActionListener {
    // set up 3 pts
    JButton[] buttons = new JButton[25];
    JLabel moneyLabel = new JLabel("Total Amount: $0");
    JButton bottomButton = new JButton("Leave and take all the money");
    JPanel centerPanel = new JPanel(new GridLayout(5,5)); 
    Container contentPane = getContentPane();
    int total = 0;
    public GetMoney() {
        super("Get Money");
        contentPane.add(moneyLabel, BorderLayout.NORTH);
        for(int i = 0; i < 25; i++) { 
           buttons[i] = new JButton();
           buttons[i].setActionCommand("" + i);
           buttons[i].addActionListener(this);
        }
        random(buttons);
        for(int i = 0; i < 25; i++) {
           centerPanel.add(buttons[i]);
        }
        contentPane.add(centerPanel);
        contentPane.add(bottomButton, BorderLayout.SOUTH);
        // 4 pts
        bottomButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                disableAll();
                moneyLabel.setText("You got $" + total + " !");

            }
        });
    }
    
    
    // 8 pts
    public void actionPerformed(ActionEvent e) {
        int x = Integer.parseInt(e.getActionCommand());
        JButton button = (JButton)e.getSource();
        if(x == 0) {
            button.setIcon(new ImageIcon("smiley.gif"));
            moneyLabel.setText("You lost all your money !");
            disableAll();

        } else {
            total+=x;
            button.setText("$"+x);
            button.setEnabled(false);
            moneyLabel.setText("Total Amount: $" + total);
        }
    }
    
    public void disableAll() {
            for(int i = 0; i < 25; i++) {
                buttons[i].setEnabled(false);
            }
            bottomButton.setEnabled(false);
        
    }
    
   public static void random(Object[] array) {
       for(int i = array.length-1; i >=0; i--) {
       int j = (int)(i*Math.random());
       Object temp = array[j];
       // swap;
       array[j] = array[i];
       array[i] = temp;
     }
   }
    
    public static void main(String[] args) {
        GetMoney f = new GetMoney();
        f.setSize(350,350);
        f.setVisible(true);
    }

}