Polish draughts

Story

Your best friend Tom is board games lover, and he plays checkers all the time like a pro! Recently he is really into digital versions of his favorite games, unfortunately he cannot find any implementation of the Polish Draughts. Give Tom your console version of this game.

What are you going to learn?

You will learn and practice how to do the following things:

• variables,
• methods,
• loops and conditionals,
• classes and instances,
• print formatting,
• user input validation,
• handle edge cases,
• access modifiers,
• OOP.

Tasks

1. There is a class Board which represents square board for Polish draughts.

   • There is a parameter n in the constructor describing the length of the side of the square, size should be an integer between 10 and 20 provided from user input.
   • There is a 2D array Pawn[][] fields which represents fields on a board. Each field can be null (empty) or a Pawn instance.
   • Pawns are created and placed only at every second field when the board is initialized. Their number is determined by board size as a 2 * n.
   • There is toString() method that overrides built-in method. This method should mark rows as a numbers and columns as a letters.
   • There is removePawn() method that removes pawn with given position from.
   • There is movePawn() method that moves pawn with given position from one field to another.

2. There is a Pawn class.

   • There is a method boolean getIsWhite() that returns true if the pawn is white and false if it's black.
   • There is a field of class Coordinates position that represent pawn coordinates on a board. Coordinates class has two fields int x and int y.
   • [Extra] There is a field boolean isCrowned that returns true if given pawn is crowned.
   • Pawn contains a method that validates given move (checks whether it's according to the game's rules) before making it.
   • [Extra] Pawn can check if it can make multiple jumps according to the rules.

3. There is a class Game which contains all game logic and actions.

   • There is a method start() that starts whole game between players.
   • There is a method playRound() that determines one round actions i.e. check who plays next or is there a winner yet.
   • There is a method that checks if starting position from user input is a valid pawn and if ending position is within board boundaries. If so, it calls tryToMakeMove() on pawn instance.
   • There is a method checkForWinner() that checks after each round is there an a winner.
   • Method checkForWinner() checks also for draws.

4. [OPTIONAL] Try to implement singleton pattern. Try to implement additional features such as crowning, multi-jumping and checking for draw.

   • Board is a singleton so it can have only one instance.
   • Crowned feature is implemented. There is a property on Pawn called boolean isCrowned that returns true if given pawn is crowned and it implements crowning rules.
   • Pawn can check if it can make multiple jumps according to the rules.

General requirements

• Whole board is redrawn in the console after each move.
• In case of an invalid input, the user is asked to input again, until receiving a valid value.

Hints

• Try implement regular draughts rules and moves at first, try to expand it after your first code works.
• You can use e.g. Singleton Design Pattern to make only one board instance.
• You can try to convert user input letters from chars to integers, this might help you find the way ASCII TABLE

Background materials

In this project your job is to implement variation of Polish draughts for two players. You also can try writing some AI to play the game.

Main rules:

• there are two players with white and black pawns. White moves first,
• size board can be picked before the game starts, but it must be an integer between 10 and 20,
• all moves and captures are made diagonally,
• pawns can also capture backward.

Optional rules:

• Multiple successive jumps forward or backward in a single turn can and must be made if after each jump there is an unoccupied square immediately beyond the enemy pawn,
• A piece is crowned if it stops on the far edge of the board at the end of its turn (that is, not if it reaches the edge but must then jump another piece backward).

Winning and draws:

• A player with no valid move remaining loses,

• Optional: The game is considered a draw when the same position repeats itself for the third time (not necessarily consecutive), with the same player having the move each time,

• A king-versus-king endgame is automatically declared a draw.

• Fields

• Methods

• Types in Java

• Clean Code in Java

• Singleton Design Pattern

• Access Modifiers