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我正在编写一个 minmax 算法作为井字游戏的人工智能，我在这里遵循了类似的指令，但是该算法似乎不够智能，即使我尝试在树中进行更深的搜索，任何人都可以帮助分析哪里出了问题？非常感谢你！

- (int) miniMax:(int)depth : (UIImage*) player {
    NSMutableArray *steps = [self generateMoves];
    
    if (depth == 0 || [steps count] == 0) {
        return [self evaluate];
    }
    
    int bestScore = player == myImg ? -1000000 : 1000000;
    int currentScore = 0;
    for (UIImageView *step in steps) {
        step.image = player;
        if (player == myImg) {
            UIImage *opp = player == xImg ? oImg : xImg;
            currentScore = [self miniMax:depth - 1 :opp];
            if (currentScore > bestScore) {
                bestScore = currentScore;
                nextStep = step;
            }
        } else {
            UIImage *opp = player == xImg ? oImg : xImg;
            currentScore = [self miniMax:depth - 1 :opp];
            if (currentScore < bestScore) {
                bestScore = currentScore;
                nextStep = step;
            }
        }
        step.image = NULL;
    }
    
    return bestScore;
}

- (int) evaluate {
    int score = 0;
    score += [self evaluateLine:img0 :img1 :img2];
    score += [self evaluateLine:img3 :img4 :img5];
    score += [self evaluateLine:img6 :img7 :img8];

    score += [self evaluateLine:img0 :img3 :img6];
    score += [self evaluateLine:img1 :img4 :img7];
    score += [self evaluateLine:img2 :img5 :img8];
    
    score += [self evaluateLine:img2 :img4 :img6];
    score += [self evaluateLine:img0 :img4 :img8];
    return score;
}

- (int) evaluateLine:(UIImageView*)img1 :(UIImageView*)img2 :(UIImageView*)img3 {
    int score = 0;
    // first cell
    if ([img1 image] == myImg) {
        score = 1;
    } else if ([img1 image] == oppImg){
        score = -1;
    }
 
    // second cell
    if ([img2 image] == myImg) {
        if (score == 1) {
            score = 10;
        } else if (score == -1) {
            return 0;
        } else {
            score = -1;
        }
    } else if ([img2 image] == oppImg){
        if (score == -1) {
            score = -10;
        } else if (score == 1) {
            return 0;
        } else {
            score = -1;
        }
    }
    
    // third cell
    if ([img3 image] == myImg) {
        if (score > 0) {
            score *= 10;
        } else if (score < 0) {
            return 0;
        } else {
            score = -1;
        }
    } else if ([img3 image] == oppImg){
        if (score < 0) {
            score *= 10;
        } else if (score > 1) {
            return 0;
        } else {
            score = -1;
        }
    }

    return score;
}

我这里使用的是：如果存在与人类玩家持有的相同图像，则得分加1。如果一行或一行或对角线有两个或三个玩家的图像，则总分分别为10和100。如果在同一行、同一列或同一对角线中同时存在“X”和“O”，则得分为 0。计算机保留上述这些的负分。

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1 回答 1

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Minimax 假设评估函数是从第一个玩家的角度出发的。你想要的是一个函数，如果第一个玩家更好，它总是具有更高的价值。

似乎您的启发式函数会根据当前玩家调整其值（我不是 Objective-C 程序员）。更改该函数，使其不知道 myImg 或 oppImg 是什么——直接使用 xImg 和 oImg。可能只是工作。

于 2014-02-16T06:55:22.423 回答