该算法运行良好，没有任何错误，但AI根本不聪明，似乎正在进行随机移动。我已经在这工作了两天，无法弄清楚我哪里出错了。有人可以帮助找到导致它无法正确移动的错误吗？
当开始游戏时，AI应该始终在索引4（中间方格）移动，除非我拿到那个位置，但它不会那样做，而且它根本不会尝试获胜。
$(document).ready(function() {
let X = {
isComputer: false,
symbol: "x",
marker: "<img src='img/x.png'>",
winMarker: "<img src='img/xWin.png'>"
}
let O = {
isComputer: false,
symbol: "o",
marker: "<img src='img/o.png'>",
winMarker: "<img src='img/oWin.png'>"
}
let game = {
board: [0,1,2,3,4,5,6,7,8],
firstTurn: X,
xScore: 0,
oScore: 0,
turnNumber: 0,
started: false
}
let winningCombos = [
[0,1,2], [3,4,5], [6,7,8],
[0,3,6], [1,4,7], [2,5,8],
[0,4,8], [2,4,6]
];
let theWinningCombo;
let player = X;
let clearBoardTimeoutID;
let ai1;
let ai2;
function clearBoardForNextGame() {
clearBoardTimeoutID =
setTimeout(function() {
$('.square').empty();
game.firstTurn = game.firstTurn == X ? O : X;
game.turnNumber = 0;
game.board = [0,1,2,3,4,5,6,7,8];
game.started = true;
}, 1500);
}
function thisPlayerWon(board, symbol) {
for (let i = 0; i < winningCombos.length; i++) {
let counter = 0;
for (let j = 0; j < winningCombos[i].length; j++) {
if (board[winningCombos[i][j]] == symbol) {
counter++;
}
if (counter == 3) {
theWinningCombo = winningCombos[i];
return true;
}
}
}
return false;
}
function showWinnerAndUpdateScore(combo, player) {
game.started = false;
combo.forEach(index => $('#' + index).html(player.winMarker));
player == X ? (game.xScore++, $('#score1').text(game.xScore)) : (game.oScore++, $('#score2').text(game.oScore))
}
function AImove(AIplayer, board) {
AIplayer = !(game.turnNumber % 2) ? game.firstTurn : (game.firstTurn == X ? O : X);
let opponent = AIplayer == X ? O : X;
let bestMove = minimax(AIplayer, board, 0);
board[bestMove] = AIplayer.symbol;
$('#' + bestMove).html(AIplayer.marker);
game.turnNumber++;
function minimax(player, board, depth) {
let spotsNotMarked = emptyBoardSpots(board);
if (thisPlayerWon(board, AIplayer.symbol)) {
return 10-depth;
}
else if (thisPlayerWon(board, opponent.symbol)) {
return depth-10;
}
else if (spotsNotMarked.length == 0) {
return 0;
}
let moves = [];
let scores = [];
for (let i = 0; i < spotsNotMarked.length; i++) {
let index = spotsNotMarked[i];
let score;
board[index] = player.symbol;
if (player == X) {
score = minimax(O, board, depth+1);
}
else {
score = minimax(X, board, depth+1);
}
scores.push(score);
board[index] = index;
moves.push(index);
}
if (player == AIplayer) {
return moves[scores.indexOf(Math.max(...scores))];
}
else {
return moves[scores.indexOf(Math.min(...scores))];
}
}
}
function emptyBoardSpots(board) {
return board.filter(square => !isNaN(square));
}
$('.AI-Switch').on('change', function() {
if (!game.started) {
this.id == "one" ? (X.isComputer = !(X.isComputer), ai1 = X) : (O.isComputer = !(O.isComputer), ai2 = O);
}
});
$('#resetButton').on('click', function() {
clearTimeout(clearBoardTimeoutID);
$('.square').empty();
$('.scores').text("0");
game.board = [0,1,2,3,4,5,6,7,8];
game.firstTurn = X;
game.xScore = 0;
game.oScore = 0;
game.turnNumber = 0;
game.started = false;
});
$('#startButton').on('click', function() {
game.started = true;
});
$('.square').on('click', function() {
if (game.started && !isNaN(game.board[this.id])) {
player = !(game.turnNumber % 2) ? game.firstTurn : (game.firstTurn == X ? O : X);
this.innerHTML = player.marker;
game.board[this.id] = player.symbol;
game.turnNumber++;
if (game.turnNumber > 3 && thisPlayerWon(game.board, player.symbol)) {
showWinnerAndUpdateScore(theWinningCombo, player);
clearBoardForNextGame();
}
else if (game.turnNumber == 9) {
clearBoardForNextGame();
}
if (O.isComputer && player == X) {
AImove(player, game.board);
}
else if (X.isComputer && player == O) {
AImove(player, game.board);
}
}
});
});
答案 0 :(得分：2)
问题是minimax的返回值：它是分数还是移动？
您认为递归调用应该返回一个分数，除了应该返回移动时的第一个调用。这确实很方便，但事情并非如此：
这意味着在递归树的一半（不在叶子上），你也会向后移动，但是你将它们视为递归树内一级的分数。显然，任何结果都没有意义。
让您的minimax函数返回分数，但也同时移动（相关时）。这可以通过返回包含两条信息的对象来完成。
这是您的AImove功能，只需进行一些修改即可实现该功能。修改后的行标有***：
function AImove(AIplayer, board) {
AIplayer = !(game.turnNumber % 2) ? game.firstTurn : (game.firstTurn == X ? O : X);
let opponent = AIplayer == X ? O : X;
let bestMove = minimax(AIplayer, board, 0).move; // *** Get move part of return value
board[bestMove] = AIplayer.symbol;
$('#' + bestMove).html(AIplayer.marker);
game.turnNumber++;
function minimax(player, board, depth) {
if (depth===2) console.log('step');
let spotsNotMarked = emptyBoardSpots(board);
if (thisPlayerWon(board, AIplayer.symbol)) {
return { score: 10-depth }; // *** Object with score (there's no move)
}
else if (thisPlayerWon(board, opponent.symbol)) {
return { score: depth-10 }; // *** idem
}
else if (spotsNotMarked.length == 0) {
return { score: 0 }; // *** idem
}
let moves = [];
let scores = [];
for (let i = 0; i < spotsNotMarked.length; i++) {
let index = spotsNotMarked[i];
let score;
board[index] = player.symbol;
if (player == X) {
score = minimax(O, board, depth+1).score; // *** Get score part
}
else {
score = minimax(X, board, depth+1).score; // *** idem
}
scores.push(score);
board[index] = index;
moves.push(index);
}
let score = (player == AIplayer ? Math.max : Math.min)(...scores); // *** Get score
return { score, move: moves[scores.indexOf(score)] }; // *** Return both move & score
}
}