private void takeTurnForPlayer(Player player) {
ArrayList<Integer> validMoves = new ArrayList<>(mBoard.getWidth());
// Iterate through each column
for (int i = 0; i < mBoard.getWidth(); i++) {
// Check if column has empty spaces available
if (mBoard.get(0, i).getValue() == BoardSpace.Value.Empty) {
// If so, add it to valid moves
validMoves.add(i);
}
}
// Choose a random available column
Random random = new Random();
int moveToTake = validMoves.get(random.nextInt(validMoves.size()));
mBoard.addPiece(moveToTake, player.getSymbol());
}
public void start() {
Logger logger = new ConsoleLogger();
logger.print("Welcome to Connect 4\n");
logger.print("\n");
// Set game state to STARTED
mGameState = GameState.STARTED;
mCurrentPlayer = 0;
printBoard();
// Continuously take turns while the game is incomplete
while (mGameState != GameState.COMPLETE) {
// If no more moves are available, set game state to complete and break out of loop
if (mBoard.isFull()) {
mGameState = GameState.COMPLETE;
continue;
}
// Otherwise, take turn for current player
Player currentPlayer = mPlayers.get(mCurrentPlayer);
takeTurnForPlayer(currentPlayer);
// Print the current state of the board
printBoard();
// If someone won, set the game state to complete
mWinner = getWinner();
if (mWinner != null) {
mGameState = GameState.COMPLETE;
continue;
}
// Otherwise, set the next player in line
mCurrentPlayer++;
if (mCurrentPlayer >= mNumberOfPlayers) mCurrentPlayer = 0;
// Amateur technique for pausing application, so we can more easily see the game progress
try {
Thread.sleep(TURN_DELAY);
} catch (InterruptedException e) {
mLogger.error(e.getMessage());
e.printStackTrace();
}
}
showResult();
}
private void printBoard() {
mLogger.print(mBoard.toString());
mLogger.print("\n");
}
/**
* @return The value of spaces with at least four matching in a row, horizontally, vertically, or
* diagonally
*/
private BoardSpace.Value getWinner() {
// Check every column
for (int column = 0; column < mBoard.getWidth(); column++) {
BoardSpace.Value previousValue = BoardSpace.Value.Empty;
BoardSpace.Value currentValue;
int consecutivePiecesOfSameValue = 1;
for (int row = 0; row < mBoard.getHeight(); row++) {
currentValue = mBoard.get(row, column).getValue();
if (currentValue == BoardSpace.Value.Empty || currentValue != previousValue) {
consecutivePiecesOfSameValue = 1;
} else { // We have a streak
consecutivePiecesOfSameValue++;
// Check if there are at least four in a row
if (consecutivePiecesOfSameValue >= 4) {
// Found a winner
return currentValue;
}
}
previousValue = currentValue;
}
}
// Check every row
for (int row = 0; row < mBoard.getHeight(); row++) {
BoardSpace.Value previousValue = BoardSpace.Value.Empty;
BoardSpace.Value currentValue;
int consecutivePiecesOfSameValue = 1;
for (int column = 0; column < mBoard.getWidth(); column++) {
currentValue = mBoard.get(row, column).getValue();
if (currentValue == BoardSpace.Value.Empty || currentValue != previousValue) {
consecutivePiecesOfSameValue = 1;
} else { // We have a streak
consecutivePiecesOfSameValue++;
// Check if there are at least four in a row
if (consecutivePiecesOfSameValue >= 4) {
// Found a winner
return currentValue;
}
}
previousValue = currentValue;
}
}
// Check diagonals from top-left to bottom-right
// Check for each diagonal from the left column
for (int row = 0; row < mBoard.getHeight(); row++) {
BoardSpace.Value previousValue = BoardSpace.Value.Empty;
BoardSpace.Value currentValue;
int consecutivePiecesOfSameValue = 1;
int checkSpaceRow = row;
int checkSpaceColumn = 0;
while (checkSpaceRow < mBoard.getHeight() && checkSpaceColumn < mBoard.getWidth()) {
currentValue = mBoard.get(checkSpaceRow, checkSpaceColumn).getValue();
if (currentValue == BoardSpace.Value.Empty || currentValue != previousValue) {
consecutivePiecesOfSameValue = 1;
} else { // We have a streak
consecutivePiecesOfSameValue++;
// Check if there are at least four in a row
if (consecutivePiecesOfSameValue >= 4) {
// Found a winner
return currentValue;
}
}
previousValue = currentValue;
checkSpaceRow++;
checkSpaceColumn++;
}
}
// Check for each diagonal from the top row
for (int column = 0; column < mBoard.getHeight(); column++) {
BoardSpace.Value previousValue = BoardSpace.Value.Empty;
BoardSpace.Value currentValue;
int consecutivePiecesOfSameValue = 1;
int checkSpaceRow = 0;
int checkSpaceColumn = column;
while (checkSpaceRow < mBoard.getHeight() && checkSpaceColumn < mBoard.getWidth()) {
currentValue = mBoard.get(checkSpaceRow, checkSpaceColumn).getValue();
if (currentValue == BoardSpace.Value.Empty || currentValue != previousValue) {
consecutivePiecesOfSameValue = 1;
} else { // We have a streak
consecutivePiecesOfSameValue++;
// Check if there are at least four in a row
if (consecutivePiecesOfSameValue >= 4) {
// Found a winner
return currentValue;
}
}
previousValue = currentValue;
checkSpaceRow++;
checkSpaceColumn++;
}
}
// Check diagonals from top-right to bottom-left
// Check for each diagonal from the right column
for (int row = 0; row < mBoard.getHeight(); row++) {
BoardSpace.Value previousValue = BoardSpace.Value.Empty;
BoardSpace.Value currentValue;
int consecutivePiecesOfSameValue = 1;
int checkSpaceRow = row;
int checkSpaceColumn = mBoard.getWidth() - 1;
while (checkSpaceRow < mBoard.getHeight() && checkSpaceColumn >= 0) {
currentValue = mBoard.get(checkSpaceRow, checkSpaceColumn).getValue();
if (currentValue == BoardSpace.Value.Empty || currentValue != previousValue) {
consecutivePiecesOfSameValue = 1;
} else { // We have a streak
consecutivePiecesOfSameValue++;
// Check if there are at least four in a row
if (consecutivePiecesOfSameValue >= 4) {
// Found a winner
return currentValue;
}
}
previousValue = currentValue;
checkSpaceRow++;
checkSpaceColumn--;
}
}
// Check for each diagonal from the top row
for (int column = 0; column < mBoard.getWidth(); column++) {
BoardSpace.Value previousValue = BoardSpace.Value.Empty;
BoardSpace.Value currentValue;
int consecutivePiecesOfSameValue = 1;
int checkSpaceRow = 0;
int checkSpaceColumn = column;
while (checkSpaceRow < mBoard.getHeight() && checkSpaceColumn >= 0) {
currentValue = mBoard.get(checkSpaceRow, checkSpaceColumn).getValue();
if (currentValue == BoardSpace.Value.Empty || currentValue != previousValue) {
consecutivePiecesOfSameValue = 1;
} else { // We have a streak
consecutivePiecesOfSameValue++;
// Check if there are at least four in a row
if (consecutivePiecesOfSameValue >= 4) {
// Found a winner
return currentValue;
}
}
previousValue = currentValue;
checkSpaceRow++;
checkSpaceColumn--;
}
}
// If we didn't find a winner, return null
return null;
}