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社区首页 >问答首页 >Othello Minimax算法在React.js中不工作

Othello Minimax算法在React.js中不工作
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Stack Overflow用户
提问于 2021-05-12 15:17:30
回答 1查看 104关注 0票数 0

我有一个问题,AI球员总是发挥第一个可用的移动,它会遇到。我试着让一个人工智能和Minimax算法一起工作。你觉得我怎么能解决这个问题?

这是代码(w/解说):

在显示代码之前先略加了解一下:

  • ,我试着把它设置成这样一种方式,即AI播放器(不管它的颜色是什么)是最大限度的玩家。因此,如果玩家的转弯是白色的,而白色是AI的,那么isMaximizing =true。
  • 我想指出这一点,这样玩家就不会混淆颜色和最大化。

在我最初使用它的地方:

代码语言:javascript
复制
// AI Hard - Return Minimax
function minimaxAI(){
    // Here's where the minimax function is initially called

    const AI = (ourPlayer === "white") ? "black" : "white"
    const squares = history[history.length - 1].slice()

    // AI is the maximizing player so we get -Infinity, it'll try to increase the value of bestScore
    let bestScore = -Infinity
    let bestMove = null
    // Perform minimax algorithm for each valid move and pick the best score
    
    // Get the valid moves for the AI player
    const AIValidMoves = checkSquaresForSides()[(AI === "black") ? 0 : 1 ]
    for (var AIMove=0;AIMove<AIValidMoves.length;AIMove++){

        // Play the AI moves and generate the new board
        const crds = AIValidMoves[AIMove].turned
        crds.unshift(AIValidMoves[AIMove].coordinates)
        const newBoard = handleMove(crds, squares,AI,false,false)

        // Check minimax for the new board
        const score = minimax(newBoard,4,false)
        
        // If score is higher than the current one, replace the highest score and the according coordinates
        if (score > bestScore || AIMove === 0) {
            bestScore = score
            bestMove = crds
        }
    }
    console.log('Final Value:')
    console.log(bestScore)

    // Play the move(this time on the real board)
    const upcomingAI = handleMove(bestMove)

    // Set it as the latest of the collection of squares
    setHistory(upcomingAI)

    // Useless to know for this issue
    setStepNumber(upcomingAI.length - 1)
}

Minimax算法本身:

代码语言:javascript
复制
function minimax(board, depth, isMaximizing) {
    const AI = (ourPlayer === "white") ? "black" : "white"
    const stones = setStoneCount(board)
    
    // If there's a winner, return Infinity, 0 or -Infinity depending on whether AI won, it is a tie or our player won
    if (stones[0] === 0 || stones[1] === 0 || stones[0] + stones[1] === 64) {
        // Return the score of the move if the game is over
        let score = (stones[(AI === "black") ? 1 : 0] === 0) ? Infinity : (stones[stones[0] === stones[1]]) ? 0 : -Infinity
        return score
    } else if (depth === 0) {
        // If the maximal depth is reached, then evaluate the current board by counting all the stones for the both sides and subtracting one from the other appropriately
        const squares = setStoneCount(board)
        let score = 0
        if (AI === "black") {
            score = squares[0] - squares[1]
        } else if (AI === "white") {
            score = squares[1] - squares[0]
        }
        return score
    }
    if (isMaximizing) {
        // Perform minimax if depth !== 0 and isMaximizing, just like we did initially
        let bestScore = -Infinity
        
        // Get the valid moves for the maximizing player
        const AIValidMoves = checkSquaresForSides()[(AI === "black") ? 0 : 1 ] // AI Moves because isMaximizing = true
        for (var AIMove=0;AIMove<AIValidMoves.length;AIMove++){
            const crds = AIValidMoves[AIMove].turned
            crds.unshift(AIValidMoves[AIMove].coordinates)
            const newBoard = handleMove(crds,board,AI,false,false)
            // check for isMaximizing
            let maximizingNext = !isMaximizing
            
            // If there's no move to make for the one side, player turn might stay the same. Here, I check for those situations
            const available = checkSquaresForSides(newBoard)
            if (available[0].length === 0) {
                if (AI === "white") {
                    maximizingNext = true
                } else {
                    maximizingNext = false
                }
            } else if (available[1].length === 0){
                if (AI === "black") {
                    maximizingNext = true
                } else {
                    maximizingNext = false
                }
            }
            
            // Perform minimax for the new board(depth is one less)
            const score = minimax(newBoard,depth - 1,maximizingNext)
            
            // If current score is higher than the highest one caught yet, it should be replaced
            if (score > bestScore) {
                bestScore = score
            }
        }
        return bestScore
    } else {
        // Perform minimax if depth !== 0 and isMaximizing
        let bestScore = Infinity

        // Get the valid squares for the minimizing player
        const PlayerValidMoves = checkSquaresForSides()[(AI === "black") ? 1 : 0 ] // Player Moves because isMaximizing = false

        // Play each move one-by-one for the minimizing player
        for (var playerMove=0;playerMove<PlayerValidMoves.length;playerMove++) {
            const crds = PlayerValidMoves[playerMove].turned
            crds.unshift(PlayerValidMoves[playerMove].coordinates)
            const newBoard = handleMove(crds,board,ourPlayer,false,false)
            // check for isMaximizing
            let maximizingNext = !isMaximizing
            
            // Just like the previous one, check whether there's an exceptional situation to be considered with the player turn
            const available = checkSquaresForSides(newBoard)
            if (available[0].length === 0) {
                if (AI === "white") {
                    maximizingNext = true
                } else {
                    maximizingNext = false
                }
            } else if (available[1].length === 0){
                if (AI === "black") {
                    maximizingNext = true
                } else {
                    maximizingNext = false
                }
            }
            
            // Perform minimax for the new board
            const score = minimax(newBoard,depth - 1,maximizingNext)

            // If the current score is lower than the lowest one obtained so far, it should be replaced
            if (score < bestScore) {
                bestScore = score
            }
        }
        return bestScore
    }
}

它最初确实起作用了,但当我对达到深度时评估董事会的方式不满意时,它就开始工作了。我改了,现在不起作用了。我不想回到前一个,因为它是不准确的。但是为什么AI玩家第一次移动,但没有正确的评估?

EN

回答 1

Stack Overflow用户

发布于 2021-05-13 10:00:46

我解决了,只是把董事会评估部分改为:

代码语言:javascript
复制
// The initial score
let score = 0
// value board for each square
const sq_val = [
    [160, -20,  20,   5,   5,  20, -20, 160],    
    [-20, -40,  -5,  -5,  -5,  -5, -40, -20],
    [20,  -5,  15,   3,   3,  15,  -5,  20],
    [5,  -5,   3,   3,   3,   3,  -5,   5],
    [5,  -5,   3,   3,   3,   3,  -5,   5],
    [20,  -5,  15,   3,   3,  15,  -5,  20], 
    [-20, -40,  -5,  -5,  -5,  -5, -40, -20],   
    [160, -20,  20,   5,   5,  20, -20, 160]
]

// Our stones' positions are looked for and the according values are added or substracted depending on whether the player found is the maximizing player or the minimizing player(AI Player: Maximizing, Our Player: Minimizing)
for (var row=0;row<8;row++)
    for (var col=0;col<8;col++) {
        if (board[row][col] === AI) {
            score += sq_val[row][col]
        } else if (board[row][col] === ourPlayer) {
            score -= sq_val[row][col]
        }
    }
}
// The score is returned
return score

顺便说一句,算法现在都设置好了,但还没有那么精确,因为我需要增加它的深度;而且为了做到这一点,我必须首先实现α-β修剪,这样我们的计算机就不会过热。另外,使函数异步将更好地提高性能。

票数 0
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页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/67506457

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