TicTacToe和Minimax [英] TicTacToe and Minimax

问题描述

我是一位年轻的程序员，正在学习python并努力实现AI(使用minimax)来玩TicTacToe.我开始在线观看教程，但是该教程使用的是JavaScript，因此无法解决我的问题.我也看过这个问题( ticticactoe的Python minimax )，但是它没有任何答案，实施方式与我的有很大不同.

I am a young programmer that is learning python and struggling to implement an AI (using minimax) to play TicTacToe. I started watching a tutorial online, but the tutorial was on JavaScript and thus couldn't solve my problem. I also had a look at this question ( Python minimax for tictactoe ), but it did not have any answers and the implementation was considerably different from mine.

您将在下面找到的代码是答案之一(@water_ghosts)所建议的编辑.

the code you will find below is an edit suggested by one of the answers (@water_ghosts).

编辑#2:我删除了possiblePositions，因为AI应该从possiblePositions中选择一个自由字段而不是一个位置(这在实现minimax时不会很聪明))

EDIT #2: I deleted possiblePositions, as the AI should choose a free field and not a place from the possiblePositions (that wouldn't make it that smart while implementing minimax :) )

现在，代码根本不会发出任何错误并且可以正常运行，但是一件小事:AI总是选择下一个可用字段.例如，在我不在的情况下，我选择了下一个自由位置，而不是阻止我的获胜选项.

Now the code doesn't give out any errors at all and functions properly, but one small thing: the AI always chooses the next available field. For example in situations where i am i move away from winning, instead of blocking my win option, it chooses the next free spot.

如果您想知道元素dict在这里做什么:我只是想确保程序选择了最佳索引...

If you're wondering what that elements dict is doing there: i just wanted to make sure the programm chose the best index...

这是我的代码:

class TicTacToe:
    def __init__(self):

        self.board = [" ", " ", " ", " ", " ", " ", " ", " ", " "]

        self.playerSymbol = ""
        self.playerPosition = []

        self.aiSymbol = ""
        self.aiPosition = []

        self.score = 0

        self.winner = None

        self.scoreBoard = {
            self.playerSymbol: -1,
            self.aiSymbol: 1,
            "tie": 0
        }

        self.turn = 0

        self.optimalMove = int()

    def drawBoard(self):
        print(self.board[0] + " | " + self.board[1] + " | " + self.board[2])
        print("___" + "___" + "___")
        print(self.board[3] + " | " + self.board[4] + " | " + self.board[5])
        print("___" + "___" + "___")
        print(self.board[6] + " | " + self.board[7] + " | " + self.board[8])

    def choice(self):

        answer = input("What do you want to play as? (type x or o) ")

        if answer.upper() == "X":
            self.playerSymbol = "X"
            self.aiSymbol = "O"
        else:
            self.playerSymbol = "O"
            self.aiSymbol = "X"

    def won(self):

        winningPositions = [{0, 1, 2}, {3, 4, 5}, {6, 7, 8}, {0, 4, 8}, {2, 4, 6}, {0, 3, 6}, {1, 4, 7}, {2, 5, 8}]

        for position in winningPositions:
            if position.issubset(self.playerPosition):
                self.winner = self.playerSymbol
                print("Player Wins :)")
                return True
            elif position.issubset(self.aiPosition):
                self.winner = self.aiSymbol
                print("AI wins :(")
                return True
        if self.board.count(" ") == 0:
            self.winner = "tie"
            print("Guess it's a draw")
            return True

        return False

    def findOptimalPosition(self):

        bestScore = float("-Infinity")
        elements = {}  # desperate times call for desperate measures

        for i in range(9):
            if self.board[i] == " ":
                self.board[i] = self.aiSymbol  # AI quasi made the move here
                if self.minimax(True) > bestScore:
                    bestScore = self.score
                    elements[i] = bestScore
                self.board[i] = " "
        return max(elements, key=lambda k: elements[k])

    def minimax(self, isMaximizing):

        if self.winner is not None:
            return self.scoreBoard[self.winner]

        if isMaximizing:
            bestScore = float("-Infinity")
            for i in range(9):
                if self.board[i] == " ":
                    self.board[i] = self.aiSymbol
                    bestScore = max(self.minimax(False), bestScore)
                    self.board[i] = " "
            return bestScore
        else:
            bestScore = float("Infinity")
            for i in range(9):
                if self.board[i] == " ":
                    self.board[i] = self.playerSymbol
                    bestScore = min(self.minimax(True), bestScore)
                    self.board[i] = " "
            return bestScore

    def play(self):

        self.choice()

        while not self.won():
            if self.turn % 2 == 0:
                pos = int(input("Where would you like to play? (0-8) "))
                self.playerPosition.append(pos)
                self.board[pos] = self.playerSymbol
                self.turn += 1
                self.drawBoard()
            else:
                aiTurn = self.findOptimalPosition()
                self.aiPosition.append(aiTurn)
                self.board[aiTurn] = self.aiSymbol
                self.turn += 1
                print("\n")
                print("\n")
                self.drawBoard()
        else:
            print("Thanks for playing :)")


tictactoe = TicTacToe()
tictactoe.play()

我来自Java背景，对此并不习惯:( 任何帮助将不胜感激

I come from a java background and am not used to this :( Any help would be highly appreciated

我愿意提出一些建议和方法来改进我的代码并解决此问题. 在此先感谢您并保持健康， 克里斯蒂

I am open to suggestions and ways to improve my code and fix this problem. Thanks in advance and stay healthy, Kristi

推荐答案

我将其发布为答案，以防万一将来有人遇到相同的问题:)

I am posting this as an answer, just in case somebody in the future stumbles upon the same problem :)

我遇到的主要问题(除了我糟糕的编程风格之外)是我忘记更新列表playerPosition和aiPosition的内容. 您可以在工作代码中查看其余的更改:

the main issue i encountered (besides my bad programming style) is that i forgot to update the contents the lists playerPosition and aiPosition. You can review the rest of the changes in the working code:

class TicTacToe:
    def __init__(self):

        self.board = [" ", " ", " ", " ", " ", " ", " ", " ", " "]

        self.playerSymbol = ""
        self.playerPosition = []

        self.aiSymbol = ""
        self.aiPosition = []

        self.winner = None

        self.scoreBoard = None

        self.turn = 0

        self.optimalMove = int()

    def drawBoard(self):
        print(self.board[0] + " | " + self.board[1] + " | " + self.board[2])
        print("___" + "___" + "___")
        print(self.board[3] + " | " + self.board[4] + " | " + self.board[5])
        print("___" + "___" + "___")
        print(self.board[6] + " | " + self.board[7] + " | " + self.board[8])

    def choice(self):

        answer = input("What do you want to play as? (type x or o) ")

        if answer.upper() == "X":
            self.playerSymbol = "X"
            self.aiSymbol = "O"
        else:
            self.playerSymbol = "O"
            self.aiSymbol = "X"

        self.scoreBoard = {
            self.playerSymbol: -1,
            self.aiSymbol: 1,
            "tie": 0
        }

    def availableMoves(self):

        moves = []
        for i in range(0, len(self.board)):
            if self.board[i] == " ":
                moves.append(i)
        return moves

    def won_print(self):
        self.won()
        if self.winner == self.aiSymbol:
            print("AI wins :(")
            exit(0)
        elif self.winner == self.playerSymbol:
            print("Player Wins :)")
            exit(0)
        elif self.winner == "tie":
            print("Guess it's a draw")
            exit(0)

    def won(self):

        winningPositions = [{0, 1, 2}, {3, 4, 5}, {6, 7, 8},
                            {0, 4, 8}, {2, 4, 6}, {0, 3, 6},
                            {1, 4, 7}, {2, 5, 8}]

        for position in winningPositions:
            if position.issubset(self.playerPosition):
                self.winner = self.playerSymbol
                return True
            elif position.issubset(self.aiPosition):
                self.winner = self.aiSymbol
                return True
        if self.board.count(" ") == 0:
            self.winner = "tie"
            return True

        self.winner = None
        return False

    def set_i_ai(self, i):
        self.aiPosition.append(i)
        self.board[i] = self.aiSymbol

    def set_clear_for_ai(self, i):
        self.aiPosition.remove(i)
        self.board[i] = " "

    def set_i_player(self, i):
        self.playerPosition.append(i)
        self.board[i] = self.playerSymbol

    def set_clear_for_player(self, i):
        self.playerPosition.remove(i)
        self.board[i] = " "

    def findOptimalPosition(self):

        bestScore = float("-Infinity")
        elements = {}  # desperate times call for desperate measures

        for i in self.availableMoves():
            self.set_i_ai(i)
            score = self.minimax(False)
            if score > bestScore:
                bestScore = score
                elements[i] = bestScore
            self.set_clear_for_ai(i)
        if bestScore == 1:
            print("you messed up larry")
        elif bestScore == 0:
            print("hm")
        else:
            print("whoops i made a prog. error")
        return max(elements, key=lambda k: elements[k])

    def minimax(self, isMaximizing):

        if self.won():
            return self.scoreBoard[self.winner]

        if isMaximizing:
            bestScore = float("-Infinity")
            for i in self.availableMoves():
                self.set_i_ai(i)
                bestScore = max(self.minimax(False), bestScore)
                self.set_clear_for_ai(i)
            return bestScore
        else:
            bestScore = float("Infinity")
            for i in self.availableMoves():
                self.set_i_player(i)
                bestScore = min(self.minimax(True), bestScore)
                self.set_clear_for_player(i)
            return bestScore

    def play(self):

        self.choice()

        while not self.won_print():
            if self.turn % 2 == 0:
                pos = int(input("Where would you like to play? (0-8) "))
                self.playerPosition.append(pos)
                self.board[pos] = self.playerSymbol
                self.turn += 1
                self.drawBoard()
            else:
                aiTurn = self.findOptimalPosition()
                self.aiPosition.append(aiTurn)
                self.board[aiTurn] = self.aiSymbol
                self.turn += 1
                print("\n")
                print("\n")
                self.drawBoard()
        else:
            print("Thanks for playing :)")


if __name__ == '__main__':
    tictactoe = TicTacToe()
    tictactoe.play()

但是如前所述，代码可能有效，但是在逻辑和结构方面存在许多问题，因此请不要直接复制粘贴:))

But as mentioned, the code may work, but there are MANY problems regarding the logic and structure, so do not straight-forward copy-paste it :))

这篇关于TicTacToe和Minimax的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！