python井字棋ai_实现AI下井字棋的alpha-beta剪枝算法（python实现）

好的，下面是实现AI下井字棋的alpha-beta剪枝算法的Python代码：

import math

MAX = math.inf
MIN = -math.inf

def minimax(board, depth, alpha, beta, is_maximizing):
    result = check_winner(board)
    if result != None:
        return result

    if is_maximizing:
        best_score = MIN
        for i in range(3):
            for j in range(3):
                if board[i][j] == ' ':
                    board[i][j] = 'X'
                    score = minimax(board, depth+1, alpha, beta, False)
                    board[i][j] = ' '
                    best_score = max(score, best_score)
                    alpha = max(alpha, best_score)
                    if beta <= alpha:
                        break
        return best_score
    else:
        best_score = MAX
        for i in range(3):
            for j in range(3):
                if board[i][j] == ' ':
                    board[i][j] = 'O'
                    score = minimax(board, depth+1, alpha, beta, True)
                    board[i][j] = ' '
                    best_score = min(score, best_score)
                    beta = min(beta, best_score)
                    if beta <= alpha:
                        break
        return best_score

def find_best_move(board):
    best_score = MIN
    best_move = None
    for i in range(3):
        for j in range(3):
            if board[i][j] == ' ':
                board[i][j] = 'X'
                score = minimax(board, 0, MIN, MAX, False)
                board[i][j] = ' '
                if score > best_score:
                    best_score = score
                    best_move = (i, j)
    return best_move

def check_winner(board):
    for i in range(3):
        if board[i][0] == board[i][1] == board[i][2] != ' ':
            return 1 if board[i][0] == 'X' else -1
        if board[0][i] == board[1][i] == board[2][i] != ' ':
            return 1 if board[0][i] == 'X' else -1
    if board[0][0] == board[1][1] == board[2][2] != ' ':
        return 1 if board[0][0] == 'X' else -1
    if board[0][2] == board[1][1] == board[2][0] != ' ':
        return 1 if board[0][2] == 'X' else -1
    for i in range(3):
        for j in range(3):
            if board[i][j] == ' ':
                return None
    return 0

board = [[' ', ' ', ' '], [' ', ' ', ' '], [' ', ' ', ' ']]

while True:
    print(board[0])
    print(board[1])
    print(board[2])
    winner = check_winner(board)
    if winner != None:
        if winner == 0:
            print("Tie!")
        else:
            print("You win!" if winner == 1 else "AI wins!")
        break
    row = int(input("Enter row (0, 1, or 2): "))
    col = int(input("Enter column (0, 1, or 2): "))
    if board[row][col] != ' ':
        print("Invalid move!")
        continue
    board[row][col] = 'O'
    winner = check_winner(board)
    if winner != None:
        if winner == 0:
            print("Tie!")
        else:
            print("You win!" if winner == 1 else "AI wins!")
        break
    row, col = find_best_move(board)
    board[row][col] = 'X'

这个代码实现了一个简单的人机对战井字棋游戏，其中AI使用了alpha-beta剪枝算法来下棋。当玩家输入坐标时，程序会将玩家的棋子放在对应的位置，并检查是否有获胜者。如果没有获胜者，AI会使用minimax算法和alpha-beta剪枝来找到最好的下棋位置，并将棋子放在那里。程序会不断循环，直到游戏结束。