#Tic-Tac-Toe 井字棋游戏

#全局常量

X="X"

O="O"

EMPTY=" "

#询问是否继续

def ask_yes_no(question):

response=None;

while response not in("y","n"):

response=input(question).lower()

return response

#输入位置数字

def ask_number(question ,low,high):

response=None

while response not in range(low,high):

response=int(input(question))

return response

#询问谁先走，先走方为X,后走方为O

#函数返回计算机方，玩家的角色代号

def pieces():

go_first=ask_yes_no("玩家你是否先走(y/n):")

if go_first=="y":

print("\n玩家你先走.")

human=X

computer=O

else:

print("\n计算机先走.")

computer=X

human=O

return computer,human

#产生新的棋盘

def new_board():

board=[]

for square in range(9):

board.append(EMPTY)

return board

#显示棋盘

def display_board(board):

board2=board[:]

for i in range(len(board)):

if board[i]==EMPTY:

board2[i]=i

print("\t",board2[0],"|",board2[1],"|",board2[2])

print("\t","----------")

print("\t",board2[3],"|",board2[4],"|",board2[5])

print("\t", "----------")

print("\t",board2[6],"|",board2[7],"|",board2[8],"\n")

#产生可以合法走棋位置序列(也就是还未下过子位置)

def legal_moves(board):

moves=[]

for square in range(9):

if board[square]==EMPTY:

moves.append(square)

return moves

#判断输赢

def winner(board):

# 所有赢得可能情况，例如(0,1,2)就是第一行，(0,4,8,)，(2,4,6)就是对角线

WAYS_TO_WIN=((0,1,2,),(3,4,5),(6,7,8),(0,3,6),(1,4,7),(2,5,8),(0,4,8),(2,4,6))

for row in WAYS_TO_WIN:

if board[row[0]]==board[row[1]]==board[row[2]]!=EMPTY:

winner=board[row[0]]

return winner

#棋盘没有空位置

if EMPTY not in board:

return "TIE"

return False

#人走棋

def human_move (board,human):

legal =legal_moves(board)

move =None

while move not in legal:

move=ask_number("你走那个位置？(0-8)：",0,9)

if move not in legal:

print("\n此位置已经落过子了")

#print("Fine...")

return move

#计算机走棋

def computer_move(board,computer ,human):

board=board[:]

#按优劣顺序排序的下棋走子

BEST_MOVES=(4,0,2,6,8,1,3,5,7) #最佳下棋位置顺序表

#如果计算机能赢，就走那个位置

for move in legal_moves(board):

board[move]=computer

if winner(board)==computer:

print("计算机下棋位置...",move)

return move

#取消走棋方案

board[move]=EMPTY

#如果玩家能赢就堵住那个位置

for move in legal_moves(board):

board[move]=human

if winner(board)==human:

print("计算机下棋位置...",move)

return move

#取消走棋方案

board[move]=EMPTY

#如果不是上面情况，也就是这一轮赢不了

#则是从最佳下棋位置表中挑出第一个合法位置

for move in BEST_MOVES:

if move in legal_moves(board):

print("计算机下棋位置....",move)

return move

#转换角色

def next_turn(turn):

if turn ==X:

return O

else:

return X

#主函数

def main():

computer,human=pieces()

turn =X

board=new_board()

display_board(board)

while not winner(board):

if turn ==human:

move=human_move(board,human)

board[move]=human

else:

move=computer_move(board,computer,human)

board[move]=computer

display_board(board)

turn=next_turn(turn) #转换角色

#游戏结束输出输赢或和棋信息

the_winner=winner(board)

if the_winner==computer:

print("计算机赢！\n")

elif the_winner==human:

print("玩家赢！\n")

elif the_winner=="TIE":

print("平局，游戏结束\n")

main()

input("按任意键退出游戏")