Fall Semester 2002

Consider the problem defined below:

import java.io.*; 

class One {
    public static void main(String[] args) throws IOException {
	String line; 
        boolean done = false; 
        BufferedReader b = 
	    new BufferedReader(new InputStreamReader(System.in));
        int sum = 0, number, computer;  
	System.out.println("Welcome to the game."); 
	System.out.println("The sum is zero."); 
	System.out.println("You choose first."); 
	do {
	    System.out.print("Choose at [" + sum + "]: "); 
            line = b.readLine(); 
            try { 
		number = Integer.parseInt(line); 
            } catch (Exception e) {
                number = 0; 
            }	    
            if (number <= 0 || number > 10) {
		System.out.println("Not a valid choice, please choose again.");
                continue; 
            } 
	    //----------------------------------------------( the user )----
	    sum += number;
	    System.out.println("The sum becomes... " + sum); 
	    if (sum >= 100) {
		System.out.println("You win."); 
		System.out.println("Thanks for playing."); 
		System.exit(0); 
	    } 
	    //----------------------------------------------( the machine )-
            computer = (int)(Math.random() * 10) + 1;
            System.out.println("The computer chooses... " + computer); 
	    sum += computer; 
	    System.out.println("The sum becomes... " + sum); 
	    if (sum >= 100) {
		System.out.println("You lose."); 
		System.out.println("Thanks for playing."); 
		System.exit(0); 
	    } 
	} while (!done); 
    }
}

Here's the program in action:

frilled.cs.indiana.edu%java One
Welcome to the game.
The sum is zero.
You choose first.
Choose at [0]: 1
The sum becomes... 1
The computer chooses... 10
The sum becomes... 11
Choose at [11]: 12
Not a valid choice, please choose again.
Choose at [11]: 1
The sum becomes... 12
The computer chooses... 7
The sum becomes... 19
Choose at [19]: 4
The sum becomes... 23
The computer chooses... 4
The sum becomes... 27
Choose at [27]: 7
The sum becomes... 34
The computer chooses... 3
The sum becomes... 37
Choose at [37]: 8
The sum becomes... 45
The computer chooses... 5
The sum becomes... 50
Choose at [50]: 6
The sum becomes... 56
The computer chooses... 7
The sum becomes... 63
Choose at [63]: 4
The sum becomes... 67
The computer chooses... 5
The sum becomes... 72
Choose at [72]: 6
The sum becomes... 78
The computer chooses... 1
The sum becomes... 79
Choose at [79]: 10
The sum becomes... 89
The computer chooses... 10
The sum becomes... 99
Choose at [99]: 2
The sum becomes... 101
You win.
Thanks for playing.
frilled.cs.indiana.edu%

• The computer and the user take turns.
• The user makes the first move, then the computer moves.
• A valid move consists of choosing a number between 1 and 10 (inclusive).
• All numbers are being added into a sum.
• The player that first turns the sum into a number >= 100 wins.

What technologies can you use?

Any of the following:

• CGI/Perl with hidden fields
• CGI/Perl with sessions (MySQL, DBI.pm, CGI.pm)
• PHP with hidden fields
• PHP with sessions

Answer: just one.

Choose one that you like best and implement a solution.

Post a working version and the source code under your protected by Thu 5:30pm.

For Thu (when we have the written exam) please be comfortable with all four technologies:

• you will have to solve a similar problem, but
• you may not have a choice of implementation technology.

Good luck and do well!