79 lines
2.6 KiB
Python
79 lines
2.6 KiB
Python
from copy import deepcopy
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State = tuple[int, list[list[int | None]]] # Tuple of player (whose turn it is),
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# and board
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Action = tuple[int, int] # Where to place the player's piece
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class Game:
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def initial_state(self) -> State:
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return (0, [[None, None, None], [None, None, None], [None, None, None]])
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def to_move(self, state: State) -> int:
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player_index, _ = state
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return player_index
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def actions(self, state: State) -> list[Action]:
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_, board = state
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actions = []
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for row in range(3):
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for col in range(3):
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if board[row][col] is None:
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actions.append((row, col))
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return actions
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def result(self, state: State, action: Action) -> State:
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_, board = state
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row, col = action
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next_board = deepcopy(board)
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next_board[row][col] = self.to_move(state)
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return (self.to_move(state) + 1) % 2, next_board
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def is_winner(self, state: State, player: int) -> bool:
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_, board = state
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for row in range(3):
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if all(board[row][col] == player for col in range(3)):
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return True
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for col in range(3):
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if all(board[row][col] == player for row in range(3)):
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return True
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if all(board[i][i] == player for i in range(3)):
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return True
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return all(board[i][2 - i] == player for i in range(3))
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def is_terminal(self, state: State) -> bool:
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_, board = state
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if self.is_winner(state, (self.to_move(state) + 1) % 2):
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return True
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return all(board[row][col] is not None for row in range(3) for col in range(3))
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def utility(self, state, player):
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assert self.is_terminal(state)
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if self.is_winner(state, player):
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return 1
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if self.is_winner(state, (player + 1) % 2):
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return -1
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return 0
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def print(self, state: State):
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_, board = state
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print()
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for row in range(3):
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cells = [
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" " if board[row][col] is None else "x" if board[row][col] == 0 else "o"
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for col in range(3)
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]
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print(f" {cells[0]} | {cells[1]} | {cells[2]}")
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if row < 2:
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print("---+---+---")
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print()
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if self.is_terminal(state):
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if self.utility(state, 0) > 0:
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print(f"P1 won")
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elif self.utility(state, 1) > 0:
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print(f"P2 won")
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else:
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print("The game is a draw")
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else:
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print(f"It is P{self.to_move(state)+1}'s turn to move")
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