algorithm - 奥赛罗极小极大算法

Question

我正在尝试使用 Minimax 算法为 Othello 实现一个人工智能播放器。电脑玩得不错，但不是很好。我在以下代码中是否正确实现了它？

Coordinate bestCoordinate = null;
public int minimax(MyButton[][] gameBoard, int depth, boolean maximizingPlayer) {
    if (depth == 0) {
        return evaluateBoard(gameBoard);
    }

    if (maximizingPlayer) {
        int bestValue = Integer.MIN_VALUE;
        LinkedList<Coordinate> moves = generateMoves(gameBoard);
        for (Coordinate move : moves) {
            MyButton[][] newBoard = cloneBoard(gameBoard);
            processMove(newBoard, newBoard[move.getxCoordinate()][move.getyCoordinate()]);
            int v = minimax(newBoard, depth - 1, !maximizingPlayer);
            if (v > bestValue) {
                bestValue = v;
                bestCoordinate = move;
            }
        }
        return bestValue;
    }
    else {
        int bestValue = Integer.MAX_VALUE;
        LinkedList<Coordinate> moves = generateMoves(gameBoard);
        for (Coordinate move : moves) {
            MyButton[][] newBoard = cloneBoard(gameBoard);
            processMove(newBoard, newBoard[move.getxCoordinate()][move.getyCoordinate()]);
            int v = minimax(newBoard, depth - 1, !maximizingPlayer);
            if (v < bestValue) {
                bestValue = v;
                bestCoordinate = move;
            }
        }
        return bestValue;
    }
}

此外，这是我的评估函数:

public int evaluateBoard(MyButton[][] gameBoard) {

    int blackPieces = 0;
    int whitePiecess = 0;

    for (MyButton[] array : gameBoard) {
        for (MyButton button : array) {
            if (button.getBackground().equals(Color.black)) {
                blackPieces++;
            } else if (button.getBackground().equals(Color.WHITE)) {
                whitePiecess++;
            }
        }
    }

    int cornerBonus = 10;
    if (gameBoard[0][0].getBackground().equals(Color.BLACK)) {
        blackPieces += cornerBonus;
    }
    if (gameBoard[0][getBoardWidth() - 1].getBackground().equals(Color.BLACK)) {
        blackPieces += cornerBonus;
    }
    if (gameBoard[getBoardHeight() - 1][0].getBackground().equals(Color.BLACK)) {
        blackPieces += cornerBonus;
    }
    if (gameBoard[getBoardHeight() - 1][getBoardWidth() - 1].getBackground().equals(Color.BLACK)) {
        blackPieces += cornerBonus;
    }
    if (gameBoard[0][0].getBackground().equals(Color.WHITE)) {
        whitePiecess += cornerBonus;
    }
    if (gameBoard[0][getBoardWidth() - 1].getBackground().equals(Color.WHITE)) {
        whitePiecess += cornerBonus;
    }
    if (gameBoard[getBoardHeight() - 1][0].getBackground().equals(Color.WHITE)) {
        whitePiecess += cornerBonus;
    }
    if (gameBoard[getBoardHeight() - 1][getBoardWidth() - 1].getBackground().equals(Color.WHITE)) {
        whitePiecess += cornerBonus;
    }
    return whitePiecess - blackPieces;
}

(电脑总是白棋，人是黑棋)。我不确定主要是因为计算机似乎无法保护角落，尽管它们提供了奖励积分。我的代码/逻辑有什么问题吗？

Answer 1

您正在更新每个深度的最佳着法。在您的函数外部创建一个名为 SEARCH_DEPTH 的常量，您每次调用该函数时都会使用它并进行 if 检查:

if(depth == SEARCH_DEPTH) {
    bestCoordinate = move;
}

此外，假设您是最大化玩家，您只想在 if(maximizingPlayer) block 中设置移动。