From f9fd2a042af10a86c69dc82c9f1659533e1a74eb Mon Sep 17 00:00:00 2001
From: Valentin Gehrke <madmaurice@zom.bi>
Date: Fri, 12 Sep 2014 16:35:57 +0200
Subject: [PATCH] TicTacToe AI
---
tictactoe.py | 157 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 157 insertions(+)
create mode 100644 tictactoe.py
diff --git a/tictactoe.py b/tictactoe.py
new file mode 100644
index 0000000..c8cd073
--- /dev/null
+++ b/tictactoe.py
@@ -0,0 +1,157 @@
+import random
+
+class Player(object):
+
+ def __init__(self,rep):
+ self.rep = rep
+
+ def __repr__(self):
+ return self.rep
+
+ def count_win_chances(self, board):
+ chances = 0
+ for line in board.get_all_lines():
+ if all( map( lambda v: v == self or v == Board.empty, line) ):
+ chances += 1
+ return chances
+
+class Board(object):
+ draw = object()
+ empty = Player(" ")
+ def __init__(self,size=3):
+ self.board = [ [Board.empty] * size for i in range(size) ]
+ self.size = size
+
+ def set(self, x, y, value):
+ if x < 0 or x >= self.size or y < 0 or y >= self.size:
+ raise Exception("Out of bounds!")
+ if value == Board.empty or isinstance(value,Player):
+ self.board[x][y] = value
+ else:
+ raise Exception("Invalid value %s" % str(value))
+
+ def get(self, x, y):
+ if x < 0 or x >= self.size or y < 0 or y >= self.size:
+ raise Exception("Out of bounds!")
+ else:
+ return self.board[x][y]
+
+ def get_all_lines(self):
+ lines = []
+ #diagonals
+ lines.append( [ self.board[xy][xy] for xy in range(self.size) ] )
+ lines.append( [ self.board[x][self.size-x-1] for x in range(self.size) ] )
+
+ #rows
+ lines += self.board
+
+ #cols
+ lines += [ [ self.board[x][y] for x in range(self.size) ] for y in range(self.size) ]
+
+ return lines
+
+ def get_empty_fields(self):
+ for x in range(self.size):
+ for y in range(self.size):
+ if self.board[x][y] == Board.empty:
+ yield (x,y)
+
+ def get_winner(self):
+ for line in self.get_all_lines():
+ if line[0] != self.empty and all(map(lambda v: v == line[0],line)):
+ return line[0]
+ for field in self.get_empty_fields():
+ return None
+ return Board.draw
+
+ def copy(self):
+ c = Board(size=self.size)
+ for x in range(self.size):
+ for y in range(self.size):
+ c.set(x,y, self.get(x,y))
+ return c
+
+ def __str__(self):
+ return ("\n-"+("*-"*(self.size-1)) +"\n").join( [ "|".join( [ str(pos) for pos in line ] ) for line in self.board ] )
+
+
+class AI(Player):
+ def play(self,enemy, board):
+ if board.get_winner() is not None:
+ raise Exception("Game over!")
+ boardcopy = board.copy()
+
+ moves = []
+
+ #Check for win chance
+ for x,y in board.get_empty_fields():
+ boardcopy.set(x,y,self)
+ # Check for win
+ if boardcopy.get_winner() == self:
+ return (x,y)
+
+ # Check for chance
+ chance = self.count_win_chances(boardcopy) - enemy.count_win_chances(boardcopy)
+
+ moves.append( (chance,(x,y)) )
+
+
+ # Check if enemy win
+ boardcopy.set(x,y,enemy)
+
+ if boardcopy.get_winner() == enemy:
+ return (x,y)
+
+ boardcopy.set(x,y,Board.empty)
+
+ moves.sort(key=lambda x: -x[0])
+
+ best_move = moves[0]
+
+ good_moves = []
+
+ for move in moves:
+ if move[0] == best_move[0]:
+ good_moves.append(move)
+
+ return random.choice(good_moves)[1]
+
+class Human(Player):
+ def play(self, enemy, board):
+ while True:
+ s = input("Player %s's turn:")
+ try:
+ (x,y) = map(int, s.split(","))
+ return (x,y)
+ except Exception:
+ print("Try again?")
+
+def rotate(l):
+ return l[1:] + l[:1]
+
+if __name__ == "__main__":
+ board = Board(size=6)
+ players = [ AI("X"), AI("O") ]
+
+ print(str(board))
+
+ while board.get_winner() is None:
+ (x,y) = players[0].play(players[1],board)
+ while board.get(x,y) != Board.empty:
+ print("Try again!")
+ (x,y) = players[0].play(players[1],board)
+
+ board.set(x,y,players[0])
+ players = rotate(players)
+
+ print()
+ print(str(board))
+
+ winner = board.get_winner()
+
+ if winner == Board.draw:
+ print("Round draw!")
+ else:
+ print("%s has won!" % str(winner) )
+
+