# 畫棋盤的函數(shù)，傳入一個放置棋子的列表
def drawBoard(board) :
 
 print(" " + board[7] + " | " + board[8] + " | " + board[9])
 print("------------")
 print(" " + board[4] + " | " + board[5] + " | " + board[6])
 print("------------")
 print(" " + board[1] + " | " + board[2] + " | " + board[3])
 
# 玩家選擇所想用的棋子種類
def inputPlayerLetter() :
 
 letter = ''
 while not (letter == 'X' or letter == 'O') :
 print("Do you want to be X or O")
 # 自動將小寫轉(zhuǎn)化為大寫
 letter = input().upper()
 
 # 如果玩家選擇的X，則自動將O賦給電腦，反之一樣
 if letter == 'X' :
 return ['X','O']
 else :
 return ['O','X']
 
# 這里隨機生成0或者1來表示誰先落子
def whoGoesFirst() :
 
 if random.randint(0,1) == 0 :
 return 'computer'
 else :
 return 'player'
 
# 如果玩家選擇y或者Y則游戲重新開始
def playAgain():
 
 print("Do you want to play again?(yes or no)")
 return input().lower().startswith('y')
 
# 將棋子放置到棋盤上面
# board參數(shù)是儲存棋子的列表
# letter參數(shù)是棋子的類型
# move是選擇將棋子放在哪
def makeMove(board, letter, move) :
 
 board[move] = letter
 
# 根據(jù)井字棋規(guī)則判斷是否獲勝
def isWinner(bo, le) :
 
 return ((bo[7] == le and bo[8] == le and bo[9] == le) or
  (bo[4] == le and bo[5] == le and bo[6] == le) or
  (bo[1] == le and bo[2] == le and bo[3] == le) or
  (bo[7] == le and bo[4] == le and bo[1] == le) or
  (bo[8] == le and bo[5] == le and bo[2] == le) or
  (bo[9] == le and bo[6] == le and bo[3] == le) or
  (bo[7] == le and bo[5] == le and bo[3] == le) or
  (bo[9] == le and bo[5] == le and bo[1] == le))
 
# 將已經(jīng)在棋盤上的棋子備份,隨時更新
def getBoardCopy(board) :
 
 dupeBoard = []
 for i in board :
 dupeBoard.append(i)
 
 return dupeBoard
 
# 判斷棋盤是否還有可落子的地方
def isSpaceFree(board, move) :
 
 return board[move] == ' '
 
# 獲取玩家落子的位置
def getPlayerMove(board) :
 
 move = ' '
 # 判斷落子的位置是否正確以及棋盤是否還能落子
 while move not in '1 2 3 4 5 6 7 8 9'.split() or not isSpaceFree(board, int(move)) :
 
 print("What is your next move?(1-9)")
 move = input()
 return int(move)
 
# 找到可以落子的地方，主要是計算機使用的
def chooseRandomMoveFromList(board, moveList) :
 
 possibleMoves = []
 for i in moveList :
 if isSpaceFree(board, i) :
  possibleMoves.append(i)
 
 if len(possibleMoves) != 0 :
 return random.choice(possibleMoves)
 else :
 return None

# 電腦落子
def getComputerMove(board, computerLetter) :
 
 # 給出棋盤上電腦和玩家棋子的類型
 if computerLetter == 'X' :
 playerLetter = 'O'
 else :
 playerLetter = 'X'
 
 for i in range(1,10) :
 # 在備份的棋盤中判斷是否有可以落子的地方
 copy = getBoardCopy(board)
 if isSpaceFree(copy, i) :
  # 如果有可以落子的地方,則先在備份的棋盤上落子
  makeMove(copy, computerLetter, i)
  # 落子后判斷電腦是否能贏,并且返回能贏的落子的位置
  if isWinner(copy, computerLetter) :
  return i
 
 for i in range(1,10) :
 copy = getBoardCopy(board)
 if isSpaceFree(copy, i) :
  # 在備份的棋盤上模擬玩家落子
  makeMove(copy, playerLetter, i)
  # 如果下一次玩家落子就可以贏,返回玩家落子的位置,用于堵住玩家
  if isWinner(copy, playerLetter) :
  return i
 
 # 隨機在四個角處落子
 move = chooseRandomMoveFromList(board,[1,3,7,9])
 if move != None :
 return move
 
 # 如果角處已被占滿,則落子在中間位置5處
 if isSpaceFree(board, 5) :
 return 5
 
 # 如果角和中間都被占滿,則隨機選擇邊上落子
 return chooseRandomMoveFromList(board,[2,4,6,8])
 
# 判斷棋盤是否已滿
def isBoardFull(board) :
 
 for i in range(1,10) :
 if isSpaceFree(board, i) :
  return False
 return True
 
 
print("Welcome to Tictactoe !!!")
 
while True :
 
 # 初始化棋盤為空
 theBoard = [' '] * 10
 # 玩家和電腦棋子類型的選擇
 playerLetter, computerLetter = inputPlayerLetter()
 # 先后順序的決定
 turn = whoGoesFirst()
 print('The ' + turn + ' will go first')
 # 游戲開始的標志位,當游戲結(jié)束時變成False
 gameIsPlaying = True
 
 while gameIsPlaying :
 # 玩家先行
 if turn == 'player' :
  drawBoard(theBoard)
  # 獲取玩家下棋的位置
  move = getPlayerMove(theBoard)
  # 將玩家的棋子傳入列表相應(yīng)的位置
  makeMove(theBoard, playerLetter, move)
 
  # 如果玩家獲勝,標志位變?yōu)镕alse
  if isWinner(theBoard, playerLetter) :
  drawBoard(theBoard)
  print("You win !")
  gameIsPlaying = False
  # 否則則判斷棋盤是否已滿
  else :
  if isBoardFull(theBoard) :
   drawBoard(theBoard)
   print("Tie")
   break
  # 若棋盤未滿,且玩家已落子,則下一次落到計算機落子
  else :
   turn = 'computer'
 # 電腦先行
 else :
  # 電腦隨機選擇位置落子
  move = getComputerMove(theBoard, computerLetter)
  makeMove(theBoard, computerLetter, move)
 
  # 如果電腦落子獲勝,則游戲結(jié)束
  if isWinner(theBoard, computerLetter) :
  drawBoard(theBoard)
  print("You lose !")
  gameIsPlaying = False
  else :
  if isBoardFull(theBoard) :
   drawBoard(theBoard)
   print("Tie")
   break
  else :
   turn = 'player'
 
 # 玩家沒有再次開始游戲,則跳出循環(huán)
 if not playAgain():
 break