游戏AI在井字游戏中的一面功能强大，而另一方面却变得愚蠢 [英] Game AI works powerfully on one side and becomes dumb on the other in Tic-Tac-Toe
本文介绍了游戏AI在井字游戏中的一面功能强大，而另一方面却变得愚蠢的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试使用PyGame和MiniMax算法在Python中制作井字游戏.当获得第一次机会(扮演"X")时，AI的表现确实很好，但是当没有机会(扮演"O")时，AI变得愚蠢到足以帮助使用户获胜.我想我知道问题出在哪里，但是更改它会使整个程序陷入混乱，并且无法按照给定的文档字符串进行操作.
我制作了两个python文件-一个用于GUI(runner.py)，另一个用于游戏和AI的逻辑(tictactoe.py).
这是游戏的逻辑:
# Import module `copy` for function `deepcopy` to deeply copy an
# original (mutable) object to save the object from mutations
import copy
X = 'X'
O = 'O'
EMPTY = None
def initial_state():
"""Returns starting state of the board
"""
return [
[EMPTY, EMPTY, EMPTY],
[EMPTY, EMPTY, EMPTY],
[EMPTY, EMPTY, EMPTY]
]
def display(board, autoprint=False):
"""Displays the board nested list as
a 3x3 matrix for board visualization
"""
vis_board = ''
for row in board:
for playr in row:
if playr is None:
playr = ' '
playr += ' '
vis_board += playr
vis_board += '\n'
if autoprint:
print(vis_board)
return vis_board
def player(board):
"""Returns player who has the next turn on a board
"""
global X, O
# Initial values for every call of the function
X_count = 0
O_count = 0
for row in board:
for playr in row:
if playr == X:
X_count += 1
elif playr == O:
O_count += 1
# `X` always starts first
if O_count < X_count:
return O
return X
def actions(board):
"""Returns set of all possible actions
(i, j) available on the board
"""
global EMPTY
action_set = set()
for i, row in enumerate(board):
for j, playr in enumerate(row):
if playr is EMPTY:
action_set.add((i, j))
return action_set
def result(board, action):
"""Returns the board that results from
making move (i, j) on the board.
"""
global EMPTY
if type(action) is not tuple or len(action) != 2:
raise Exception('invalid action taken')
# Using `deepcopy` to make a deepcopy of *board*
# as duplication by slicing entire list and by
# type conversion is not working poperly
dup_board = copy.deepcopy(board)
# Unpack the coordinates as `I` and `J`
I, J = action
# Check if place has not already been used
if dup_board[I][J] is EMPTY:
dup_board[I][J] = player(dup_board)
else:
raise Exception('invalid action taken')
return dup_board
def is_full(board):
"""Returns True if all places have been occupied, else returns False
"""
global EMPTY
for row in board:
for playr in row:
if playr is EMPTY:
return False
return True
def winner(board):
"""Returns the winner of the game, if there is one.
"""
winr = None # Initial declaration to avoid errors if no winner found
# Check diagonally
if (board[1][1] == board[0][0] and board[0][0] == board[2][2])\
or (board[1][1] == board[0][2] and board[0][2] == board[2][0]):
winr = board[1][1]
return winr
for i in range(3):
# Check each row for three-in-a-row
if board[i][0] == board[i][1] and board[i][1] == board[i][2]:
winr = board[i][1]
break
# Check each column for three-in-a-column
elif board[0][i] == board[1][i] and board[1][i] == board[2][i]:
winr = board[1][i]
break
return winr
def terminal(board):
"""Returns True if game is over, False otherwise.
"""
if winner(board) is None and not is_full(board):
return False
return True
def utility(board):
"""Returns 1 if X has won the game, -1 if O has won, 0 otherwise.
"""
global X, O
if terminal(board):
winr = winner(board)
if winr == X:
util = 1
elif winr == O:
util = -1
else:
util = 0
return util
return None
def get_best_score(board, is_max_turn):
"""Returns the best value of values of all possible moves
"""
if utility(board) is not None:
return utility(board)
scores = []
# Recursively help `minimax` choose the best action
# in `actions` of *board* by returning the best value
for action in actions(board):
rslt = result(board, action)
scores.append(get_best_score(rslt, not is_max_turn))
return max(scores) if is_max_turn else min(scores)
def minimax(board):
"""Returns the optimal action for the current player on the board.
"""
if terminal(board):
return None
best_score = -float('inf') # Least possible score
best_action = None
for action in actions(board):
rslt = result(board, action)
score = get_best_score(rslt, False)
if score > best_score:
best_score = score
best_action = action
return best_action
GUI代码文件:
# Import module `PyGame` for a GUI
import pygame
import sys
import time
# Import module `tictactoe` (from the same folder as
# this file `__file__`) for the logic of the game's AI
import tictactoe as ttt
pygame.init()
size = width, height = 600, 400
# Colors
black = (0, 0, 0)
white = (255, 255, 255)
screen = pygame.display.set_mode(size)
mediumFont = pygame.font.Font('OpenSans-Regular.ttf', 24)
largeFont = pygame.font.Font('OpenSans-Regular.ttf', 40)
moveFont = pygame.font.Font('OpenSans-Regular.ttf', 60)
user = None
board = ttt.initial_state()
ai_turn = False
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
screen.fill(black)
# Let user choose a player.
if user is None:
# Draw title
title = largeFont.render('Play Tic-Tac-Toe', True, white)
titleRect = title.get_rect()
titleRect.center = (round(width/2), 50)
screen.blit(title, titleRect)
# Draw buttons
playXButton = pygame.Rect(round(width/8), round(height/2), round(width/4), 50)
playX = mediumFont.render('Play as X', True, black)
playXRect = playX.get_rect()
playXRect.center = playXButton.center
pygame.draw.rect(screen, white, playXButton)
screen.blit(playX, playXRect)
playOButton = pygame.Rect(5*round(width/8), round(height/2), round(width/4), 50)
playO = mediumFont.render('Play as O', True, black)
playORect = playO.get_rect()
playORect.center = playOButton.center
pygame.draw.rect(screen, white, playOButton)
screen.blit(playO, playORect)
# Check if button is clicked
click, _, _ = pygame.mouse.get_pressed()
if click == 1:
mouse = pygame.mouse.get_pos()
time.sleep(0.5)
if playXButton.collidepoint(mouse):
user = ttt.X
elif playOButton.collidepoint(mouse):
user = ttt.O
else:
# Draw game board
tile_size = 80
tile_origin = (width / 2 - (1.5 * tile_size),
height / 2 - (1.5 * tile_size))
tiles = []
for i in range(3):
row = []
for j in range(3):
rect = pygame.Rect(
round(tile_origin[0]+j*tile_size),
round(tile_origin[1]+i*tile_size),
round(tile_size), round(tile_size)
)
pygame.draw.rect(screen, white, rect, 3)
if board[i][j] != ttt.EMPTY:
move = moveFont.render(board[i][j], True, white)
moveRect = move.get_rect()
moveRect.center = rect.center
screen.blit(move, moveRect)
row.append(rect)
tiles.append(row)
game_over = ttt.terminal(board)
player = ttt.player(board)
# Show title
if game_over:
winner = ttt.winner(board)
if winner is None:
title = f'Game Over: Tie.'
else:
title = f'Game Over: {winner} wins.'
elif user == player:
title = f'Play as {user}'
else:
title = f'AI thinking...'
title = largeFont.render(title, True, white)
titleRect = title.get_rect()
titleRect.center = (round(width/2), 30)
screen.blit(title, titleRect)
# Check for AI move
if user != player and not game_over:
if ai_turn:
time.sleep(0.5)
move = ttt.minimax(board)
board = ttt.result(board, move)
ai_turn = False
else:
ai_turn = True
# Check for a user move
click, _, _ = pygame.mouse.get_pressed()
if click == 1 and user == player and not game_over:
mouse = pygame.mouse.get_pos()
for i in range(3):
for j in range(3):
if (board[i][j] == ttt.EMPTY and tiles[i][j].collidepoint(mouse)):
board = ttt.result(board, (i, j))
if game_over:
againButton = pygame.Rect(round(width/3), round(height-65), round(width/3), 50)
again = mediumFont.render('Play Again', True, black)
againRect = again.get_rect()
againRect.center = againButton.center
pygame.draw.rect(screen, white, againButton)
screen.blit(again, againRect)
click, _, _ = pygame.mouse.get_pressed()
if click == 1:
mouse = pygame.mouse.get_pos()
if againButton.collidepoint(mouse):
time.sleep(0.2)
user = None
board = ttt.initial_state()
ai_turn = False
pygame.display.flip()
这些是提出这些问题的组织给出的答案的旁注:
- 不更改编号.参数或任何功能中的参数本身.
- 遵循所有函数编写的文档字符串
- 可以根据需要定义新功能
如果有任何错误/错误导致AI以'O'演奏时哑巴，请告知我.我相信该错误在utility中，但是我不能更改代码，因为它是不允许的(写在文档字符串中).
谢谢！
问题已经基本解决，但是AI有时会变得愚蠢，例如不尝试使用相反的符号来阻止用户的移动，等等.
解决方案
best_score = -float('inf') # Least possible score
您需要根据要为其计算移动量的玩家来改变此值.我认为正因为如此，消极的玩家选择了随机/第一个合理的举动.
我实施了2次minimax和相关的启发式方法，并且总是发现使用"negamax"方法效果最好，因为您不必担心何时根据玩家应用max和min. >
I am trying to make a Tic-Tac-Toe game in Python using PyGame and the MiniMax algorithm. The AI plays really well when given the first chance (playing as 'X'), but becomes dumb enough to help the user win when not given the first chance (playing as 'O'). I think I know what the problem is but changing it is messing with the whole program and is not going by the given docstrings.
I've made two python files - one for the GUI (runner.py) and the other for the logic behind the game and the AI (tictactoe.py).
This is the logic behind the game:
# Import module `copy` for function `deepcopy` to deeply copy an
# original (mutable) object to save the object from mutations
import copy
X = 'X'
O = 'O'
EMPTY = None
def initial_state():
"""Returns starting state of the board
"""
return [
[EMPTY, EMPTY, EMPTY],
[EMPTY, EMPTY, EMPTY],
[EMPTY, EMPTY, EMPTY]
]
def display(board, autoprint=False):
"""Displays the board nested list as
a 3x3 matrix for board visualization
"""
vis_board = ''
for row in board:
for playr in row:
if playr is None:
playr = ' '
playr += ' '
vis_board += playr
vis_board += '\n'
if autoprint:
print(vis_board)
return vis_board
def player(board):
"""Returns player who has the next turn on a board
"""
global X, O
# Initial values for every call of the function
X_count = 0
O_count = 0
for row in board:
for playr in row:
if playr == X:
X_count += 1
elif playr == O:
O_count += 1
# `X` always starts first
if O_count < X_count:
return O
return X
def actions(board):
"""Returns set of all possible actions
(i, j) available on the board
"""
global EMPTY
action_set = set()
for i, row in enumerate(board):
for j, playr in enumerate(row):
if playr is EMPTY:
action_set.add((i, j))
return action_set
def result(board, action):
"""Returns the board that results from
making move (i, j) on the board.
"""
global EMPTY
if type(action) is not tuple or len(action) != 2:
raise Exception('invalid action taken')
# Using `deepcopy` to make a deepcopy of *board*
# as duplication by slicing entire list and by
# type conversion is not working poperly
dup_board = copy.deepcopy(board)
# Unpack the coordinates as `I` and `J`
I, J = action
# Check if place has not already been used
if dup_board[I][J] is EMPTY:
dup_board[I][J] = player(dup_board)
else:
raise Exception('invalid action taken')
return dup_board
def is_full(board):
"""Returns True if all places have been occupied, else returns False
"""
global EMPTY
for row in board:
for playr in row:
if playr is EMPTY:
return False
return True
def winner(board):
"""Returns the winner of the game, if there is one.
"""
winr = None # Initial declaration to avoid errors if no winner found
# Check diagonally
if (board[1][1] == board[0][0] and board[0][0] == board[2][2])\
or (board[1][1] == board[0][2] and board[0][2] == board[2][0]):
winr = board[1][1]
return winr
for i in range(3):
# Check each row for three-in-a-row
if board[i][0] == board[i][1] and board[i][1] == board[i][2]:
winr = board[i][1]
break
# Check each column for three-in-a-column
elif board[0][i] == board[1][i] and board[1][i] == board[2][i]:
winr = board[1][i]
break
return winr
def terminal(board):
"""Returns True if game is over, False otherwise.
"""
if winner(board) is None and not is_full(board):
return False
return True
def utility(board):
"""Returns 1 if X has won the game, -1 if O has won, 0 otherwise.
"""
global X, O
if terminal(board):
winr = winner(board)
if winr == X:
util = 1
elif winr == O:
util = -1
else:
util = 0
return util
return None
def get_best_score(board, is_max_turn):
"""Returns the best value of values of all possible moves
"""
if utility(board) is not None:
return utility(board)
scores = []
# Recursively help `minimax` choose the best action
# in `actions` of *board* by returning the best value
for action in actions(board):
rslt = result(board, action)
scores.append(get_best_score(rslt, not is_max_turn))
return max(scores) if is_max_turn else min(scores)
def minimax(board):
"""Returns the optimal action for the current player on the board.
"""
if terminal(board):
return None
best_score = -float('inf') # Least possible score
best_action = None
for action in actions(board):
rslt = result(board, action)
score = get_best_score(rslt, False)
if score > best_score:
best_score = score
best_action = action
return best_action
The GUI code file:
# Import module `PyGame` for a GUI
import pygame
import sys
import time
# Import module `tictactoe` (from the same folder as
# this file `__file__`) for the logic of the game's AI
import tictactoe as ttt
pygame.init()
size = width, height = 600, 400
# Colors
black = (0, 0, 0)
white = (255, 255, 255)
screen = pygame.display.set_mode(size)
mediumFont = pygame.font.Font('OpenSans-Regular.ttf', 24)
largeFont = pygame.font.Font('OpenSans-Regular.ttf', 40)
moveFont = pygame.font.Font('OpenSans-Regular.ttf', 60)
user = None
board = ttt.initial_state()
ai_turn = False
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
screen.fill(black)
# Let user choose a player.
if user is None:
# Draw title
title = largeFont.render('Play Tic-Tac-Toe', True, white)
titleRect = title.get_rect()
titleRect.center = (round(width/2), 50)
screen.blit(title, titleRect)
# Draw buttons
playXButton = pygame.Rect(round(width/8), round(height/2), round(width/4), 50)
playX = mediumFont.render('Play as X', True, black)
playXRect = playX.get_rect()
playXRect.center = playXButton.center
pygame.draw.rect(screen, white, playXButton)
screen.blit(playX, playXRect)
playOButton = pygame.Rect(5*round(width/8), round(height/2), round(width/4), 50)
playO = mediumFont.render('Play as O', True, black)
playORect = playO.get_rect()
playORect.center = playOButton.center
pygame.draw.rect(screen, white, playOButton)
screen.blit(playO, playORect)
# Check if button is clicked
click, _, _ = pygame.mouse.get_pressed()
if click == 1:
mouse = pygame.mouse.get_pos()
time.sleep(0.5)
if playXButton.collidepoint(mouse):
user = ttt.X
elif playOButton.collidepoint(mouse):
user = ttt.O
else:
# Draw game board
tile_size = 80
tile_origin = (width / 2 - (1.5 * tile_size),
height / 2 - (1.5 * tile_size))
tiles = []
for i in range(3):
row = []
for j in range(3):
rect = pygame.Rect(
round(tile_origin[0]+j*tile_size),
round(tile_origin[1]+i*tile_size),
round(tile_size), round(tile_size)
)
pygame.draw.rect(screen, white, rect, 3)
if board[i][j] != ttt.EMPTY:
move = moveFont.render(board[i][j], True, white)
moveRect = move.get_rect()
moveRect.center = rect.center
screen.blit(move, moveRect)
row.append(rect)
tiles.append(row)
game_over = ttt.terminal(board)
player = ttt.player(board)
# Show title
if game_over:
winner = ttt.winner(board)
if winner is None:
title = f'Game Over: Tie.'
else:
title = f'Game Over: {winner} wins.'
elif user == player:
title = f'Play as {user}'
else:
title = f'AI thinking...'
title = largeFont.render(title, True, white)
titleRect = title.get_rect()
titleRect.center = (round(width/2), 30)
screen.blit(title, titleRect)
# Check for AI move
if user != player and not game_over:
if ai_turn:
time.sleep(0.5)
move = ttt.minimax(board)
board = ttt.result(board, move)
ai_turn = False
else:
ai_turn = True
# Check for a user move
click, _, _ = pygame.mouse.get_pressed()
if click == 1 and user == player and not game_over:
mouse = pygame.mouse.get_pos()
for i in range(3):
for j in range(3):
if (board[i][j] == ttt.EMPTY and tiles[i][j].collidepoint(mouse)):
board = ttt.result(board, (i, j))
if game_over:
againButton = pygame.Rect(round(width/3), round(height-65), round(width/3), 50)
again = mediumFont.render('Play Again', True, black)
againRect = again.get_rect()
againRect.center = againButton.center
pygame.draw.rect(screen, white, againButton)
screen.blit(again, againRect)
click, _, _ = pygame.mouse.get_pressed()
if click == 1:
mouse = pygame.mouse.get_pos()
if againButton.collidepoint(mouse):
time.sleep(0.2)
user = None
board = ttt.initial_state()
ai_turn = False
pygame.display.flip()
These are the sidenotes for the answers given by the organization that gave these questions:
- No changing the no. of parameters or the parameters themselves in any functions.
- Follow the docstrings written in all functions
- New functions may be defined as you wish
Please let me know if there are any bugs/errors which are causing the AI to be dumb when playing as 'O'. I believe the bug is in utility, but I can't change the code because it is not allowed (written in the docstrings).
Thank you!
Edit: The problem has been ALMOST solved, but the AI becomes dumb sometimes, like not trying to block the user's move with the opposite symbol, etc.
解决方案
best_score = -float('inf') # Least possible score
you need to vary this according to the player for which you calculate the move. I think because of this the negative player is choosing random/first plausible move.
I have implemented minimax and related heuristics like 2 times, and always found that using the "negamax" approach worked best, since you don't need to worry about when to apply max and when min based on the player.
这篇关于游戏AI在井字游戏中的一面功能强大，而另一方面却变得愚蠢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！
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