NIM (基本AI策略)游戏

Question

我试着在python中创建NIM游戏。我研究了几个关于如何总是在NIM比赛中获胜的视频。最后，我找到了一个方法，并且能够在我的代码中实现它。这就是结果..。

#---------------------
#      NIM GAME
#  Author : Akil Riaz
#---------------------

import random
import time

def welcome_message():
    print("""
----------------------------------------------------------------------------
                        WELCOME TO THE GAME OF NIM!
----------------------------------------------------------------------------
Rules: 1 - The user plays against the computer.
       2 - Only 1-3 sticks can be taken at a time.
       3 - The person who is left with the last stick is the loser.
       4 - Have FUN!
----------------------------------------------------------------------------
""")

def display_board(board):
    print("\n----------------------------------------------------------------------------")
    print("      ",*board, sep="   ")
    print("----------------------------------------------------------------------------\n")

def who_starts(question):
    choice = None
    while choice not in ("F", "S","f","s"):
        choice = input(question)
        if choice.upper() == "F":
            f_player = "USER"
            s_player = "USER"
        elif choice.upper() == "S":
            f_player = "CMP"
            s_player  = "CMP"
        else:
            print("\nInvalid choice. Please re-enter your choice.")

    return f_player, s_player

def users_pick(question,minStick,maxStick,userIn,board):
    print("\n--USER'S TURN--")
    while userIn not in range(minStick, maxStick) or userIn >= len(board):
        try:
            userIn = int(input(question))
            if userIn not in range(minStick, maxStick) or userIn >= len(board):
                print("\nYou can cannot choose that many sticks!")
                userIn = int(input(question))

        except Exception as e:
            print("\nAn error has occured.\nError: " + str(e) + "\nPlease re-enter your choice.")

    f_player = "CMP"

    return userIn, f_player

def update_board(board,move):
    valid_moves = (1,2)
    if len(board) > move:
        for i in  range(move):
            board.remove("/")
        return board
    elif len(board) <= move:
        if move in valid_moves:
            for i in range(move):
                board.remove("/")
            return board
        else:
            print("\n" + str(move) + " sticks cannot be taken.\nThe move you made was inavalid. Please  re-enter.")
            return board

def computers_move(board,userIn,s_player,winning_position,earlier_move):
    best_move = 1
    print("\n--COMPUTER'S TURN--")

    if s_player == "CMP" and winning_position == False:
        if len(board) % 4 ==1:
            best_move = 0
            while best_move not in range(1,len(board)+1):
                best_move = random.randint(1,3)
        else:
            if userIn + earlier_move < 4:
                best_move = 4 - (userIn + earlier_move)
                winning_position = True
            elif userIn + earlier_move > 4:
                best_move = 8 - (userIn + earlier_move)
                winning_position = True

    elif s_player == "USER" or winning_position == True:
        best_move = 4 - userIn

    earlier_move = best_move

    print("\nThe computer chooses to remove...")
    time.sleep(1)
    print(": " + str(best_move) + " stick(s).")
    for sticks in range(best_move):
        board.remove("/")

    f_player = "USER"
    return board, f_player, winning_position, earlier_move

def game_over(board,f_player):
    if len(board) == 1 and f_player == "USER":
        winner = "COMPUTER"
        loser = "USER"
    elif len(board) == 1 and f_player == "CMP":
        winner = "USER"
        loser = "COMPUTER"
    else:
        winner = None

    return winner, loser

def keepPlaying():
    while True:
        another_go = input("\nDo you want to play again?[Y/N]: ")
        if another_go in ("y","Y"):
            return True
        elif another_go in ("n","N"):
            return False
        else:
            print("\nInavlid choice. Please re-enter.")

def main():
    anotherGo = True
    welcome_message()
    while anotherGo == True:
        earlier_move = 0
        winning_position = False
        nimBoard = ["/","/","/","/","/","/","/","/","/","/","/","/","/","/","/","/","/"]
        winner = None
        userIn = 0
        print("----------------------------------------------------------------------------")
        display_board(nimBoard)
        print("\nWe begin with " + str(len(nimBoard)) + " sticks.")
        f_player, s_player = who_starts("\nDo you want to start first or second? [F for fisrt/S for second]: ")
        while len(nimBoard) != 1:
            if f_player == "USER":
                time.sleep(0.5)
                userIn,f_player = users_pick("\nEnter your choice [1, 2 or 3]: ", 1, 4, 20,nimBoard)
                nimBoard = update_board(nimBoard,userIn)
                display_board(nimBoard)
                print("\nThere are " + str(len(nimBoard)) + " stick(s) remaining.")
            else:
                time.sleep(1)
                nimBoard, f_player,winning_position, earlier_move = computers_move(nimBoard,userIn,s_player,winning_position,earlier_move)
                time.sleep(1)
                display_board(nimBoard)
                print("\nThere are " + str(len(nimBoard)) + " stick(s) remaining.")
        time.sleep(1)
        print("\nFinally...\nOnly one stick remains...")
        game_winner, game_loser = game_over(nimBoard,f_player)
        time.sleep(1)
        print("\nThe " + game_loser + " is left with the last stick and so he is the loser...")
        print("\nThe winner of the game is...\n: " + str(game_winner))
        anotherGo = keepPlaying()
        time.sleep(1)
    print("\nThank you for playing!")
    print("\n--GAME OVER--")

if __name__ ==  "__main__":
    main()

我没有遵循传统的方法，有不同的行/成堆的棍子，因为我发现这太具有挑战性(尽管我将在以后尝试)。这台电脑大部分时间都赢了。但是，如果用户知道我使用的策略，那么它是可以战胜的。

但我仍然觉得还有改进的余地。有什么可以改进的吗？

如果你们能提供任何简单的效率改进或任何形式的逻辑改进，我将不胜感激。

刚刚对程序做了一个简单的改进，计算机使用它的早期移动来确定一个更好的移动来击败用户.谢谢你的投票！)

Answer 1

通用编码风格和其他有用的技巧

提示1使用条件时，不需要键入x == True，这意味着：

while anotherGo == True:

可以是：

while anotherGo:

提示2.不要毫无意义地使用time.sleep。它可能会造成混淆，为什么你要使用它，我认为，你使用它只是为了使程序不太快，但.你为什么要那样做？)

提示3使用if/else时，可以将通用代码移到条件的末尾或开头，这样可以删除代码重复：

if f_player == "USER":
    time.sleep(0.5)
    userIn,f_player = users_pick("\nEnter your choice [1, 2 or 3]: ", 1, 4, 20,nimBoard)
    nimBoard = update_board(nimBoard,userIn)
    display_board(nimBoard)
    print("\nThere are " + str(len(nimBoard)) + " stick(s) remaining.")
else:
    time.sleep(1)
    nimBoard, f_player,winning_position, earlier_move = computers_move(nimBoard,userIn,s_player,winning_position,earlier_move)
    time.sleep(1)
    display_board(nimBoard)
    print("\nThere are " + str(len(nimBoard)) + " stick(s) remaining.")

变成：

if f_player == "USER":
    userIn,f_player = users_pick("\nEnter your choice [1, 2 or 3]: ", 1, 4, 20,nimBoard)
    nimBoard = update_board(nimBoard,userIn)

else:
    nimBoard, f_player,winning_position, earlier_move = computers_move(nimBoard,userIn,s_player,winning_position,earlier_move)

display_board(nimBoard)
print("\nThere are " + str(len(nimBoard)) + " stick(s) remaining.")

提示4如果您的所有打印都以换行开始，您可以考虑创建一个助手函数，这样您就不必每次都重新键入它：

def printn(s):
    print("\n" + s)

提示5为这些“魔术数字”创建常量。当我读到：

users_pick("\nEnter your choice [1, 2 or 3]: ", 1, 4, 20,nimBoard)

提示6您不支付每写字符，使用有意义的变量名称

您可以考虑将其命名为userIn，而不是有一个名为userInput的变量。这是..。更多的字符，但它所做的也更清楚

我需要检查函数定义，看看1,4,20是什么意思。如果您有名为MIN_STICK = 1, MAX_STICKS=4, USERIN=20的常量。

Python技巧

提示1如果多次创建具有相同值的数组，则可以：

# Notice how nice it is not to have to count to see the number of sticks
["/"] * 17

而不是：

["/","/","/","/","/","/","/","/","/","/","/","/","/","/","/","/","/"]

但我也认为你根本不需要这个数组。您可以简单地将棒数保持为int，并在必要时减少它。这个数组用于打印电路板，所以不应该将显示逻辑与游戏逻辑混合，这样可以使代码更易于维护和读取。

提示2只使用一种命名样式

您可以将snake_case和camelCase混合到您的代码中，这使得代码更难阅读。由于您使用的是Python，所以您应该坚持使用snake_case。

代码“清洁”

在users_pick方法中，您传递一个高于最大接受值的userIn，这样您的while循环才能工作(我怀疑)。不要这样做，事实上，您根本不应该将userIn作为参数传递，因为您完全忽略了输入。

再次出现在users_pick。这样做：userIn not in range(minStick, maxStick)可能看起来“很棒”，但它也意味着每次您调用它时都会生成一个范围，只为了检查值是否在其中，为什么不使用速度更快、更多的userIn < minStick or userIn > maxStick .合乎逻辑。

我不确定这是否是复制/粘贴错误，但在who_starts方法中，您将f_player和s_player设置为相同的值。

总之，我认为您应该尝试将代码中的显示逻辑和游戏逻辑分开。您在用户输入方面做得很好，但例如，您不需要保留一个/数组来查看游戏的位置。

Answer 2

这已经是很久以前的事了，但是已经对我自己的版本进行了编码，对您的代码进行了一些注释。

一般来说：

• 你可以做得更简单。特别是，不需要winning_position和earlier_move变量，只需知道len(board) % 4的值就可以得到所需的一切。
• 无论是计算机还是用户首先播放，也不应该改变算法的第一步。

详情如下：

• 不要使用拒绝: best_move =0的for循环，而best_move不在范围内(1，len(板)+1)：best_move = random.randint(1,3)

当您只需使用min时：

        best_move = random.randint(1,min(3,len(board))

• @ieatbagels的所有评论都是相关的。

我提供了一个基于罗塞塔码版本的更简单的版本(但在Rosetta的初始条件下，计算机总是获胜)

  #!python3
  import random
  misere=1 # 0 for "normal game", 1 for "misere game"
  if misere: print("Py Nim, misere game: don't take last token")
  else:      print("Py Nim, normal game: be the one to take last token")
  
  def get_tokens(tokens):
      take=0
      while (take < 1 or take > min(3,tokens)):
          take = int(input("How many tokens would you like to take? "))
  
      tokens = tokens - take
      print(f'You take {take} tokens.')
      print(f'{tokens} tokens remaining.\n')
      if tokens==misere:
          print ('You win!')
          return 0
      elif tokens==0:
          print('Strange way of losing, this was a misere game...')
          return 0
      else:
          return comp_turn(tokens)
  
  def comp_turn(tokens):
      take = (tokens-misere) % 4
      if take==0:
          take=random.randint(1,3)
      tokens = tokens - take
      print (f'Computer takes {take} tokens.')
      print (f'{tokens} tokens remaining.\n')
      if tokens==misere:
          print ('Computer wins!')
          return 0
      return tokens
  
  tokens = random.randint(12,16)
  print (f'We start with {tokens} tokens.')
  if (input("Should the computer play first? (y/n)").upper()=="Y"):
      tokens=comp_turn(tokens)
  while (tokens > 0):
      tokens=get_tokens(tokens)

如果你用多少个记号来回答电脑是否先玩，你总是可以赢的。