我在创建井字游戏的无敌AI时遇到了困难。

我一直在谷歌搜索并使用The Coding Train的教程 – 然而，AI似乎仍然在随机选择方格。尽管它选择方格的背后肯定有逻辑，但我无法弄清楚这个逻辑是什么！

这是我的codepen – https://codepen.io/kath-ldn/pen/oNLZqrp，我已经在下面复制了相关的代码片段。

如果有人能看一下，我将不胜感激。我已经卡了好几天了，无法找出问题所在。

//functions to assess winning combosfunction equals3(a, b, c) {    return a === b && b === c && a !== "";}function checkWinner(){    let winner = null;    if (equals3(gameBoard[0], gameBoard[1], gameBoard[2])) {        winner = gameBoard[0];    };    if (equals3(gameBoard[3], gameBoard[4], gameBoard[5])) {        winner = gameBoard[3];    };    if (equals3(gameBoard[6], gameBoard[7], gameBoard[8])) {        winner = gameBoard[6];    };    if (equals3(gameBoard[0], gameBoard[3], gameBoard[6])) {        winner = gameBoard[0];    };    if (equals3(gameBoard[1], gameBoard[4], gameBoard[7])) {        winner = gameBoard[1];    };    if (equals3(gameBoard[2], gameBoard[5], gameBoard[8])) {        winner = gameBoard[0];    };    if (equals3(gameBoard[0], gameBoard[4], gameBoard[8])) {        winner = gameBoard[0];    };    if (equals3(gameBoard[2], gameBoard[4], gameBoard[6])) {        winner = gameBoard[2];    };    let openSpots = 0;    for (let i = 0; i < gameBoard.length; i++) {        if (gameBoard[i] === "") {            openSpots = openSpots + 1;        };    };    if (winner === null && openSpots === 0) {        return 'tie';    } else {        return winner;    };};let scores = {  X: 10,  O: -10,  tie: 0};//function to create impossible-to-beat AI using minimax algorithmfunction bestMove() {    let bestScore = -Infinity;    let move;    for (let i = 0; i < gameBoard.length; i++) {      if (gameBoard[i] === "") {        gameBoard[i] = AI;        let score = minimax(gameBoard, 0, false);        gameBoard[i] = "";        if (score > bestScore) {        bestScore = score;        move = i;        }      }        }    gameBoard[move] = AI;};//minimax functionfunction minimax(gameBoard, depth, isMaximizing){  let result = checkWinner();  if (result !== null) {    return scores[result];  }  if (isMaximizing) {    let bestScore = -Infinity;    for (let i = 0; i < gameBoard.length; i++) {      if (gameBoard[i] === "") {        gameBoard[i] = AI;        let score = minimax(gameBoard, depth + 1, false);        gameBoard[i] = "";        bestScore = Math.max(score, bestScore);      }    }    return bestScore;  } else {    let bestScore = Infinity;    for (let i = 0; i < gameBoard.length; i++) {      if (gameBoard[i] === "") {        gameBoard[i] = human;        let score = minimax(gameBoard, depth + 1, true);        gameBoard[i] = "";        bestScore = Math.min(score, bestScore);      }    }    return bestScore;  }};

回答：

你正在遍历整个棋盘并对每个方格调用minimax，这是不必要的，而且会非常慢。你只需要像这样调用一次即可：

move, score = minimax(gameBoard, 8, true)

我不确定是否需要，但我建议从checkWinner函数中返回0而不是返回’tie’字符串。否则，从例如1和’tie’中选择最大/最小值似乎很困难。

然后在你的minimax函数中，你需要更改一些东西来实际返回它找到的最佳移动。抱歉如果有任何编程语言问题，我习惯使用Python。我希望你明白我的意思：

//minimax functionfunction minimax(gameBoard, depth, isMaximizing){  let result = checkWinner();  if (result !== null) {    return None, scores[result];  }  if (isMaximizing) {    let bestScore = -Infinity;    for (let i = 0; i < gameBoard.length; i++) {      if (gameBoard[i] === "") {        gameBoard[i] = AI;        let score = minimax(gameBoard, depth - 1, false)[1];        gameBoard[i] = "";        if score > bestScore:            bestScore = score            bestMove = gameBoard[i]      }    }    return bestMove, bestScore;  } else {    let bestScore = Infinity;    for (let i = 0; i < gameBoard.length; i++) {      if (gameBoard[i] === "") {        gameBoard[i] = human;        let score = minimax(gameBoard, depth - 1, true)[1];        gameBoard[i] = "";        if score < bestScore:            bestScore = score            bestMove = gameBoard[i]      }    }    return bestMove, bestScore;  }};