Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

IN PYTHON Pleases!! B. Tic-Tac-Toe The game of Tic-Tac-Toe (or Naughts and Cross

ID: 3924333 • Letter: I

Question

IN PYTHON Pleases!!

B. Tic-Tac-Toe The game of Tic-Tac-Toe (or Naughts and Crosses) is an ancient game in which 2 players alternate turns placing either X's or O's on a 3x3 square grid. One player places X's (crosses) on the grid and the opposing player places O's (naughts). The first player to place 3 consecutive X's (or O's) on any row, column or diagonal of the grid wins the game. If all 9 grid cells are occupied without either player winning, the game is declared a draw.

For this problem, you will represent the game 'grid' using a multidimensional (nested) list. The grid representation consists of a 3-element list in which each element represents a row. Each row is another list representing the three columns. Unoccupied grid locations are represented using null strings. For example, this is how the grid would appear before anyone makes a move:

[['', '', ''], ['', '', ''], ['', '', '']]

Given the following game state (after several 'moves'):

O X

X O

X O

The resulting grid list would be as follows:

[['O', '', 'X'], ['X', 'O', ''], ['X', '', 'O']]

Write a pure function named gameState that takes a single list argument representing the grid and determines the current state of the game: player X has won, player O has won, the game is a draw, or none of those. Your function should return a single character string as follows: 'X' if player X has won the game, 'O' if player O has won the game, 'D' if the game is a draw (all cells occupied but neither player has won) and "" (null string) if none of these conditions exist. (Hint: use a loop to compare each element of the main diagonal with all the elements of its intersecting row and column, and then check the two diagonals)

Write a separate non-pure function (procedure) named testTTT that will test your function as follows:

1. Represent the four game configurations as nested lists using the format described above. You do not have to input them into your procedure, simply declare them:

X Wins:

X O

X O

X O

O Wins:

O X

X O

X O

Draw:

O X O

X X O

X O X

No wins,

No draw:

X O

X O

X O

2. Call the gameState function to determine the game state.

3. Print the appropriate message for each game state (as determined by the gameState function):

"X wins"

"O wins"

"Draw"

"NO Win, No Draw"

Explanation / Answer

def print_board(board):

   print "The board look like this: "

   for i in range(3):
       print " ",
       for j in range(3):
           if board[i*3+j] == 1:
               print 'X',
           elif board[i*3+j] == 0:
               print 'O',  
           elif board[i*3+j] != -1:
               print board[i*3+j]-1,
           else:
               print ' ',
          
           if j != 2:
               print " | ",
       print
      
       if i != 2:
           print "-----------------"
       else:
           print
          
def print_instruction():
   print "Please use the following cell numbers to make your move"
   print_board([2,3,4,5,6,7,8,9,10])


def get_input(turn):

   valid = False
   while not valid:
       try:
           user = raw_input("Where would you like to place " + turn + " (1-9)? ")
           user = int(user)
           if user >= 1 and user <= 9:
               return user-1
           else:
               print "That is not a valid move! Please try again. "
               print_instruction()
       except Exception as e:
           print user + " is not a valid move! Please try again. "
      
def check_win(board):
   win_cond = ((1,2,3),(4,5,6),(7,8,9),(1,4,7),(2,5,8),(3,6,9),(1,5,9),(3,5,7))
   for each in win_cond:
       try:
           if board[each[0]-1] == board[each[1]-1] and board[each[1]-1] == board[each[2]-1]:
               return board[each[0]-1]
       except:
           pass
   return -1

def quit_game(board,msg):
   print_board(board)
   print msg
   quit()

def main():
  
   # Start Game
   # Change turns
   # Checks for winner
   # Quits and redo board
  
   print_instruction()

   board = []
   for i in range(9):
       board.append(-1)

   win = False
   move = 0
   while not win:

       # Print board
       print_board(board)
       print "Turn number " + str(move+1)
       if move % 2 == 0:
           turn = 'X'
       else:
           turn = 'O'

       # Get player input
       user = get_input(turn)
       while board[user] != -1:
           print "Invalid move! Cell already taken. Please try again. "
           user = get_input(turn)
       board[user] = 1 if turn == 'X' else 0

       # Continue move and check if end of game
       move += 1
       if move > 4:
           winner = check_win(board)
           if winner != -1:
               out = "The winner is "
               out += "X" if winner == 1 else "O"
               out += ""
               quit_game(board,out)
           elif move == 9:
               quit_game(board,"No winner")

if __name__ == "__main__":
   main()