Assignment #2: Connect Four

Due: Monday, December 9 at 4pm.

Design Due: in class on or before Tuesday, November 19th

No late work will be accepted for a grade.

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Motivation: Why do this?

It is getting close to the end of the semester and since you and your friends are so busy with classes, you have not had the opportunity to hang out together. Therefore, you have set yourself to the task of finding a bonding activity. Inspiration has just struck: a game! A challenge requiring thought and at least two people. The game to rule all games: a connect four tournament has been scheduled at the end of the semester. To ensure that your team has the best chance of winning, you have the inspiration to create a practice connect four game so that you and your friends will be the champions at the tournament.  As an aspiring programmer, you've decided to implement a Java program so that everyone on your hall can practice with each other. Your program allows the user to choose the size of the board and pit their talents against another player.  This task is described in more detail below. In this project you will design, code, and test your connect four database program.

Required Reading

Read Chapters 8, 9, 12 (sections 12.1 and 12.2), the Java IO web page, and the Exceptions web page.

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Goals: What we hope to learn.

The goals of this assignment are:

• To write a program almost from scratch.
• To use Java's standard I/O package as an alternative to the Javabook package.
• To use files as a means of persistent (permanent) storage.
• To parse files (recover the data stored in them).
• Practice handling Exceptions.
Use arrays of arrays to represent 2-dimensional data.
• To put into practice all of the good programming skills you have learned thus far.
• Have Fun!

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Game Overview: What's Going to Be Involved?

In this assignment, you will be writing a program called ConnectFour that will let users play games of connect four. As games are played, the win/loss/draw records of all the players will be updated. Furthermore, you will be saving games to files so that you can postpone them and continue bonding with your friends later.

The medium for these games will be the black console window, where you will be prining out a character representation of a connect four game. Here is an example of a game in progress:

| x - x o o - o |
| o - o x o - x |
| o - x o x x o |
| o - o x o o x |
| x - o o x x x |
| x - o x x o x |
-----------------
  1 2 3 4 5 6 7  

In other words, we you not be using any javabook packae classes. Instead, you'll use many of the provided JAVA standard utility and input/output classes.

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Game Rules: What Is Connect Four?

• Connect Four is a two player game.
• The board game is a two-dimensional grid of points where playing chips may be placed.
• Each player has a different color (or symbol for) their chips.
• The board game starts out empty.
• Players take turns placing their chips on the board, one at a time.
• A playing chip is placed on the board by choosing a column into which to "drop" the chip. The chip starts in the highest row and then then "falls" down to the lowest point available in that column.
• A column may become full and then no more playing chips may be dropped into that column.
• A player wins the game as soon as four of his playing chips occupy consecutive horizontal, vertical, or diagonal points on the game board.
• If all of the points on the board fill up without any player winning, then the game ends in a draw.

| - - - - - - - |
| - - - - - - - |
| - - - o x x - |
| - - o x x o - |
| - X X X X o - |
| - o o x o o - |
-----------------
  1 2 3 4 5 6 7  

| - - - - - - - |
| - - - - X - - |
| - - - o X x - |
| - - o x X o - |
| - - x x X o - |
| - o o x o o - |
-----------------
  1 2 3 4 5 6 7  

| - - - - - - - |
| - - - - o - - |
| - - - o X x - |
| - - o X x o - |
| - - X x x o - |
| - X o x o o - |
-----------------
  1 2 3 4 5 6 7  

| x o x o x o x |
| o x o x o x o |
| x o x o x o x |
| x o x o x o x |
| o x o x o x o |
| x o x o x o x |
-----------------
  1 2 3 4 5 6 7  

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Requirements: Here's What will Get You Full Credit.

Game Basics

• Each game will have a name.
• The game will be played on the input/output (black window) console. This means that the game board will be redrawn (printed to the console) as a bunch of characters.
• The users will also use this console window for input.
• WE WILL NOT BE USING ANY JAVABOOK CLASSES IN THIS ASSIGNMNET.
• Each Player will have a unique name.
• For each game, each player will choose a unique character to represent their chips on the console board.
• The character for an empty space must be the dash, '-', so players may not use this as their own.
• Your program, once running, will be using several files as a means of persistent (long-term) storage.

• As games of connect four are played, you will keep a record of all of the players. This will include the player's name, their number of wins, their number of losses, and their number of draws (in that order) up until that point.
• The file name should be "statistics.txt".
• Each line of the file should contain all the information for one single player.
• Separate the player's information with the pipe character, '|', and also end each line with the pipe character.

  Here is an example of stored information from a hypothetical a statistics file:

     statistics.txt   
  --------------------
  |                  |
  |   Ellen|13|6|2|  |
  |   Marie|2|21|6|  |
  |   Thomas|0|1|0|  |
  |                  |
  --------------------
  

  This file shows that three players have played games so far. The first player's name is "Ellen," and Ellen so far has won 13 games, lost 6 games, and drew 2 games. Marie has won 2 games, lost 21 games, and drew 6 times. Thomas has won no games, lost one game, and drew no games.

• Every time a new peice is added during a game, the state of that game (what the board looks like) should be saved in a file, so that you can later retreive that game's information, and continue playing.
• The name of the text file saving that game's state should have the same name, and have a cn4 extension (end with the string ".cn4". For example, if a new game is started called "myFirstGame", then the file that always saves the state of that game should be a file called "myFirstGame.cn4".
• In addition to where peices are, you should also save the names of the players, their own board chip characters, whose turn it is, and the dimensions of the board.
• Becasue the file names depend upon the game's name, it will be possible to overrite a game file by starting a new game with the same name.

  Here is an example of what could work:

     myFirstGame.cnc4   
  ----------------------
  |                    |
  |   Ellen|*|turn|    |
  |   Marie|&|         |
  |   6|7|             |
  |   -|-|-|-|-|-|-|   |
  |   -|-|-|-|-|-|-|   |
  |   -|-|-|&|-|-|-|   |
  |   -|-|-|*|*|-|-|   |
  |   -|-|-|&|*|&|-|   |
  |   -|*|-|&|&|*|-|   |
  |                    |
  ----------------------
  

  This file coild be interpretes as, Ellen and Marie are playing a game that was called myFirstGame. Ellen's chip character is * and Marie's chip character is &. It will be Ellen's turn as soon as the game is resumed. The game board has 6 rows and 7 columns, and the current chips are as shown.

• There is no required format for this file. However, it is recommended that you "chunk" your information in some logical or practical way, and always end each information "chunk" with the pipe character, '|'.

• Your main class MUST be called ConnectFour and the source code must appear in a file called ConnectFour.java. You will create this file.
• There are no other restrictions for what classes you need to have or how to structure your program.
• The program will start by verifying that the players statistics file exists. If it does not, then you must create a new, blank statistics file.
• Then the program will print out a main menu of options to the console window, and get the user's selection. In effect, you are making a console version of a ListBox.

• The main menu will have the following options:
  

  Display Player Statistics
  Start New Game
  Continue Saved Game
  Exit
  

  
  
  
• If Display Player Statistics is selected, then all of the informatino in the statistics file should be printed, in some clear and logical format, to the console window.
• After the statistics are shown, you should reprint the main menu.



• If Start New Game is slected, the you should prompt the users for the name of the new game, the names of each of the players, their chip characters, and the number of rows and coloumns of the game board.
• For each input, you should make sure that the values entered are valid, and immediately repeat a prompt whenever an invalid value is entered.
• Player names must be unique from each other, must not contain any numbers in it, and must not contain the pipe character '|'.
• Player chip characters, for each individual game, must be unique, and must be neither the empty space character '-', nor the pipe character '|'.
• The number of rows and columns of the game board must each be greater than or equal to 4 and less than or equal to 99.
• A new game file should be created with the appropriate name and with all the appropriate values.
• Normal game play should then ensue.



• If Continue Saved Game is selected, the users should be prompted to enter in the name of the game to be continued.
• If the game file does not exist, you should print a message to the console saying that the file was not found, and then reprint the main menu.
• If the game file was found, you should read the game file, grabbing all data in it, and normal game play should ensue.



• If Exit is selected, you should execute the method System.exit(0);.

• The first step in normal game play is to print out to the console the current game board. While there is no required format for this beyond displaying the chips and empty spaces, "prettier" outputs are always nicer. For example, it is sometimes hard to determine which column a chip is in if the columns aren't numbered on the screen. An example of output is shown below for six rows and seven columns:
  

  | - - - - - - - |
  | - - - - - - - |
  | - - - - - - - |
  | - - - - - - - |
  | - - - - - - - |
  | - - - - - - - |
  -----------------
    1 2 3 4 5 6 7  
  

• After displaying the game board, you should check if the game is over.
• If the game is over:

  Print the result of the game to the console window.

  Next, read in and store the entire players statistics file in local memory. Then you should search your local data for the names of the players involved, and update their statistics accordingly. Then write out the entire data back to the file.

  Finally, reprint the main menu.

• If the game is not yet over:

  Print out the name of the player whose turn it is to place a chip.

  Prompt the user for a selection. There should be a choice for every column and also a choice to quit the current game.

  If the selection made is to quit the current game, you should reprint the main menu.

  If the selection is a column choice, then proceed to place that chip, and update the game file with the current game state.

  If the slection made is invalid for any reason at all, then print out a message telling why the choice is invalid. Then reprint the game board, the current player whose turn it is, and the options.

• As always, you required to follow the commenting and style guides.

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Useful Classes: What you will and won't need.

Much of this program will reply upon good input / output to both the console and also various data files. Several standard JAVA classes work together in a fairly complex way to accomplish this. Use the following Java API classes to complete this program. Click on links below for Java API documentation.

Useful classes in the Java I/O package (import java.io.*):

• File
• BufferedReader
• FileReader
• PrintWriter
• FileWriter

Useful classes in the Java util package: (import java.util.*):

• StringTokenizer

Useful class in your project stationery (no import needed):

• FileFormatVerifier

Useful objects (see the Java API documentation for System):

• System.out
• System.in

DO NOT USE ANY OF THE JAVABOOK2 CLASSES!
One of the goals of this assignment is for you to learn how to do console-based input/output.

DO NOT USE THE VECTOR CLASS!
One of the goals of this assignment is for you to learn how to do basic array operations.

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Coding

Use the stationery file Assignment2 from cs302. Remember to save this as Assignment2 in your U:\private\cs302\ folder. Refer to Lesson 2 Step 2: How to create a new project if you need help creating a project.

To use an incremental coding approach when creating your instantiable classes, you can begin by coding and testing each method one at a time, starting with a constructor. Use your main method in the ConnectFour class to send messages to test these methods as they are coded. When a main method is used in this manner it is called a driver program. Once the instantiable class is completed, replace the test messages in main with the desired main program.

As you are coding, don't forget to follow the commenting and style requirements.

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Testing

Once the program is coded you are not done. You still need to determine that your program works correctly and robustly. A correct program is one where each operation adheres exactly to the specifications laid out in the assignment description. A robust program is one that doesn't crash when unexpected or erroneous situations occur such as when the user enters invalid input. Error detection and resolution is an important aspect of this assignment. There are many places where the user's input can cause an error and your program must give clear error messages and must not crash or lose information from your files. Unless otherwise specified, after an error message is displayed, the prompt that appeared before the invalid input was entered is redisplayed.

For numeric input, make sure that numbers are entered (i.e. catch NumberFormatExceptions), and that they are reasonable (e.g. you cannot have a negative number for copyright year). If there is an invalid input, display the error message below before redisplaying the prompt for input.

Invalid Input.  Try again.

Ensure that no input contain '|' (i.e. pipe) characters. They may contain other characters, including ':' (i.e. colon) characters. If they contain any pipes, remove the pipes from the input value before adding them to the database. An empty string is considered invalid input.Display an error message and re-prompt the user to enter. .

Several other common error situations that your program needs to handle include:

·  reading from a non-existent file

·  playing out of bounds

·  invalid menu choices

This list is not exhaustive. You need to ensure that your program behaves well for both expected and unexpected situations.

To receive full credit,  your code must compile and run correctly. It should not cause any exceptions that are not caught. Your program must display the menus with the options in the order specified and it must not ask the user for any additional information. You also must follow these commenting and style requirements.

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At Home

What to do to work at home.

• If this is your first time working at home, see the working at home page.
• Download the Assignment2.zip file to your CS302 folder.
• Unzip this file in your CS302 folder. You should see a folder named Assignment2. If you are using an older version of WinZip, you must install version 7 from DoIt's Electronic shelf.
• Start CodeWarrior. Choose File|Open. Navigate to your CS302/Assignment2 folder and open the ConnectFour project file.
• You're ready to work at home.

Warning: If you are having difficulty with the installation, then you should do your work in the CS computer labs. Problems with installation are not an acceptable excuse for not completing your work by the due date.

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Hints:

Some tips to get you started.

·  START EARLY!

·  Read Chapter 8 for information about processing Strings and characters.

·  Read Chapter 9 for information about using arrays.

·  Read the Java IO web page for information about Input/Output (I/O).

·  See ConsoleIO.java for an example of console input and output.

·  See FileIO.java for an example of file input and output.

·  Test for error situations on each operation before starting the next operation.

·  You will need to create new classes.  See Step 5:  How to add a source file to an existing project of the Lesson 2 tutorial if you need help adding new source files.

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Hand-in Requirements:

What you must hand in for this assignment.

Use the Handin program to hand in the files listed below.  See Step 7: How to hand-in your  work of the Lesson 2 tutorial for instructions on how to use the Handin program.

• ConnectFour.java (see commenting and style requirements)
• *.java other java source files you create
• feedback.txt

These files must be handed in anytime prior to the due date. Note: You may hand in your files before the deadline as many times as you wish. We suggest that you use your hand-in directory to keep your most recent working copy as you develop your solution.

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Solution

No solution will be provided for this assignment.

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© 2002
arman@cs.wisc.edu
blbowers@cs.wisc.edu
seabold@cs.wisc.edu
thien@cs.wisc.edu
votruba@cs.wisc.edu

modified from an assignment originally written by Jim Skrentny © 2001
skrentny@cs.wisc.edu