/**
* The main method of the class. Carries out the playing of a game of takeaway or evaluates the
* best play from a given position.
*
* @param args Used to specify the number of pennies to start with and the style of play.
*/
public static void main(String[] args) {
// The current position
TAPosition position = null;
// An instance of the evaluator to run game-play
GameEvaler robot = new GameEvaler();
// The best choice given a specific position on the board
TAMove bestChoice;
// Make sure that the correct number of CLAs were supplied
if (args.length != 1 && args.length != 2) {
System.err.println("Usage: java TakeAway [play|auto] num_pennies");
System.exit(0);
}
// Run the most basic function of the program
// Determine the best move given a position from the CLI
else if (args.length == 1) {
position = setPosition(args[0]);
bestChoice = (TAMove) robot.evaluatePosition(position, 0, false)[0];
System.out.println("The best move would be to take " + bestChoice.getMove() + " pennies.");
System.exit(0);
}
// Run the game in human play mode
if (args[0].toUpperCase().equals("PLAY")) {
position = setPosition(args[1]);
playWithHuman(position);
}
// Run the game in auto play mode (robot on robot)
else if (args[0].toUpperCase().equals("AUTO")) {
position = setPosition(args[1]);
playAuto(position);
}
// If auto or play was not selected then the usage is invalid
// This displays the appropriate message and exits gracefully.
else {
System.err.println("Usage: java TakeAway [play|auto] num_pennies");
System.exit(0);
}
}
/**
* Method for auto play. Will simulate a game between two computer players. @_position The initial
* position of the game.
*
* @return The score of the game.
*/
public static int playAuto(Position _position) {
// Current position of the game
TAPosition position = (TAPosition) _position;
// Make a game evaluator to make game choices
GameEvaler robot = new GameEvaler();
// Holder for the best choice given a specific position
Object[] robotChoice;
TAMove bestMove;
// Initialize the robot id to 0 as robot 0 goes first
int robotID = 0;
// Keep playing until one player wins
while (!position.isFinal()) {
robotChoice = robot.evaluatePosition(position, 0, false);
bestMove = (TAMove) robotChoice[0];
System.out.println("Robot " + robotID + " will take " + bestMove.getMove() + " pennies.");
position = (TAPosition) robotChoice[1];
System.out.println(
"After their move there are " + position.getPosition() + " left in the stack.\n");
// Switch players
robotID ^= 0x0001;
}
// Say who won
System.out.println("Robot " + robotID + " is the winner.");
return position.getScore();
}
/**
* Method to simulate the playing of a game of take-away with one human and one automated player.
* The human will go first.
*
* @param _position The initial position.
* @return The resulting score.
*/
public static int playWithHuman(Position _position) {
// Set the initil position
TAPosition position = (TAPosition) _position;
// Make a robot to decide what play is best
GameEvaler robot = new GameEvaler();
// Holder for the best options given a position
Object[] robotChoice;
TAMove bestMove;
// The input from the human player
int humanChoice;
// Continue to play until a final position is reached
while (!position.isFinal()) {
// The players input
String line;
// Flag to determine if the player has selected a valid move
boolean validMove = false;
// Scanner to receive player input
Scanner myScanner = new Scanner(System.in);
// Ask the player for a move until a valid move is entered
while (!validMove) {
// Prompt player for input
System.out.println("Your move. Choose 1, 2 or 3.");
line = myScanner.nextLine();
// See if the players move is valid
// and act accordingly
try {
humanChoice = Integer.parseInt(line);
if (humanChoice > 0 && humanChoice < 4) {
position = (TAPosition) position.getResultPosition(new TAMove(humanChoice));
validMove = true;
} else throw new Exception();
} catch (Exception e) {
System.out.println("I'm sorry, that's not a valid move");
}
}
// Reset the flag
validMove = false;
System.out.println(
"After your move there are " + position.getPosition() + " left in the stack.\n");
// As long as the game isn't over get the computer
// players next move
if (!position.isFinal()) {
robotChoice = robot.evaluatePosition(position, 0, false);
bestMove = (TAMove) robotChoice[0];
System.out.println("I believe my best move is " + bestMove.getMove());
position = (TAPosition) robotChoice[1];
System.out.println(
"After my move there are " + position.getPosition() + " left in the stack.\n");
}
}
return position.getScore();
}
