很难将Alpha-beta修剪实现为minimax算法

我很难让Alpha-beta修剪正常工作。 我有一个函数极小极大算法,我试着去适应,但没有用。我在上使用了该示例 Wikipedia

目前,该算法似乎在大多数情况下都按预期运行,但不管怎样,它都会选择第一个测试节点。

这可能是由于缺乏理解,但我已经花了几个小时阅读了这篇文章。让我困惑的是,在零和博弈中,算法如何知道当达到深度极限时哪个节点是最佳选择;在哪一点上,我们还不能确定哪位球员会从这一举动中受益最多,是吗?

不管怎样,我的。cpp如下。无论是我原来的极大极小函数和任何帮助将不胜感激!

AIMove ComputerInputComponent::FindBestMove() {

const Graph<HexNode>* graph = HexgameCore::GetInstance().GetGraph();

std::vector<AIMove> possibleMoves;

FindPossibleMoves(*graph, possibleMoves);

AIMove bestMove = AIMove();

int alpha = INT_MIN;
int beta = INT_MAX;
int depth = 6;

Node* currentNode;

for (const AIMove &move : possibleMoves) {

    std::cout << move << std::endl;

    graph->SetNodeOwner(move.x, move.y, (NodeOwner)aiPlayer);
    int v = MiniMaxAlphaBeta(*graph, depth, alpha, beta, true);
    graph->SetNodeOwner(move.x, move.y, NodeOwner::None);

    if (v > alpha) {
        alpha = v;
        bestMove.x = move.x;
        bestMove.y = move.y;
    }
}
return bestMove;

}

template<typename T>

int ComputerInputComponent::minimaxpalphabeta(常量图和图形、int深度、int alpha、int beta、bool isMaximiser){

std::vector<AIMove> possibleMoves;
FindPossibleMoves(graph, possibleMoves);

if (lastTestedNode != nullptr) {
    Pathfinder pathFinder;
    bool pathFound = pathFinder.SearchForPath(lastTestedNode, graph.GetMaxX(), graph.GetMaxY());
    if (pathFound) {
        //std::cout << "pathfound-" << std::endl;
        if ((int)lastTestedNode->GetOwner() == aiPlayer) {
            std::cout << "cpuWin-" << std::endl;
            return 10;
        } 
        else if ((int)lastTestedNode->GetOwner() == humanPlayer) {
            std::cout << "playerWin-" << std::endl;
            return -10;
        }
    }
    else {
        if (depth == 0) {           
            //std::cout << "NoPath-" << std::endl;
            return 0;
        }
    }
}


if (isMaximiser) {// Max
    int v = -INT_MAX;
    for (const AIMove &move : possibleMoves) {
        graph.SetNodeOwner(move.x, move.y, (NodeOwner)aiPlayer);
        graph.FindNode(move.x, move.y, lastTestedNode);
        v = std::max(alpha, MiniMaxAlphaBeta(graph, depth - 1, alpha, beta, false));
        alpha = std::max(alpha, v);
        graph.SetNodeOwner(move.x, move.y, NodeOwner::None);
        if (beta <= alpha)
            break;
    }
    return v;
}
else if (!isMaximiser){ // Min
    //std::cout << "Human possiblMoves size  = " << possibleMoves.size() << std::endl;
    int v = INT_MAX;
    for (const AIMove &move : possibleMoves) {
        graph.SetNodeOwner(move.x, move.y, (NodeOwner)humanPlayer);
        v = std::min(beta, MiniMaxAlphaBeta(graph, depth - 1, alpha, beta, true));
        beta = std::min(beta, v);
        graph.SetNodeOwner(move.x, move.y, NodeOwner::None);
        if (beta <= alpha)
            break;
    }
    return v;
}

}