"""Broken tic-tac-toe game""" # MCS 275 Spring 2022 - David Dumas # Inspired by an example from https://github.com/satwikkansal/wtfpython#-a-tic-tac-toe-where-x-wins-in-the-first-attempt # Warning: link above contains major spoilers, as well as some crude language. # You don't need to look at that link at all, and *definitely* shouldn't look # until after you're done. def winner(b): """Given a TTT board `b`, determine who has won and return. If no one has won, return None""" # Row of three for row in b: if row[0] == " ": # First row entry is blank; ignore! continue if row[0]==row[1] and row[1]==row[2]: return row[0] # Column of three for i in range(3): if b[0][i] == " ": # First column entry is blank; ignore! continue if b[0][i]==b[1][i] and b[1][i]==b[2][i]: return b[0][i] # Diagonals if b[1][1] != " ": # Middle entry not blank, so diagonal win # is a possibility. if b[0][0] == b[1][1] and b[1][1]==b[2][2]: return b[0][0] if b[0][2] == b[1][1] and b[1][1]==b[2][0]: return b[0][2] # implicit return None def print_board(b): """Show the board with 1-based coordinates""" print(" A|B|C") for i,r in enumerate(b): print("{}".format(i+1),"|".join(r)) if i<2: print("---+-+-") COLS = ["a","b","c"] def apply_move(b,player,move): """Modify board b (list of lists) to account for move in string `move`. If the move is illegal, raises an exception.""" move = move.strip().lower() if len(move)!=2: raise Exception("Valid move is two characters (e.g. A2 or B3)") if move[0] not in COLS: move = move[::-1] if move[0] not in COLS: raise Exception("No column spec found") j = COLS.index(move[0]) i = int(move[1])-1 if b[i][j] != " ": raise Exception("Another move already filled that position") b[i][j] = player if __name__=="__main__": print("Tic-tac-toe: enter moves by coordinates (e.g. A1 or B3)") print() empty_row = [" "] * 3 # create a row of blanks board = [ empty_row ] * 3 # create empty 3x3 grid cur,other = "X","O" while True: print_board(board) print() w = winner(board) if w: print("+----------------+") print("| Player {} wins! |".format(w)) print("+----------------+") break print("It is {}'s turn.".format(cur,other)) m = input("Move? ") print() try: apply_move(board,cur,m) except Exception: print("That move was not recognized, or not possible.\n") continue # switch active player cur,other = other,cur