| 1 | import numpy as np |
| 2 | |
| 3 | class Board: |
| 4 | WHITE = -1 |
| 5 | BLACK = 1 |
| 6 | EMPTY = 0 |
| 7 | |
| 8 | def __init__(self) -> None: |
| 9 | '''Initiliaze the Othello game board with a 8x8 numpy matrix''' |
| 10 | self.board = np.array([0]*8, dtype = np.int8) # initiliasing 1D array with the first row of 8 zeroes |
| 11 | self.board = self.board[np.newaxis, : ] # expanding 1D array to 2D array |
| 12 | for _ in range(3): # increasing rows till 8 |
| 13 | self.board = np.concatenate((self.board, self.board), axis = 0) |
| 14 | |
| 15 | # initiliasing the centre squares |
| 16 | self.board[3, 3] = self.board[4,4] = Board.WHITE |
| 17 | self.board[3, 4] = self.board[4,3] = Board.BLACK |
| 18 | |
| 19 | self.black_disc_count = 2 |
| 20 | self.white_disc_count = 2 |
| 21 | |
| 22 | def all_legal_moves(self, PLAYER: int) -> set: |
| 23 | '''Return all legal moves for the player''' |
| 24 | OPPONENT = Board.WHITE if PLAYER == Board.BLACK else Board.BLACK |
| 25 | |
| 26 | all_legal_moves = set() |
| 27 | for row in range(8): |
| 28 | for col in range(8): |
| 29 | if self.board[row, col] == PLAYER: |
| 30 | all_legal_moves.update(self.legal_moves(row, col)) |
| 31 | |
| 32 | return all_legal_moves |
| 33 | |
| 34 | def legal_moves(self, row: int, col: int) -> list: |
| 35 | '''Return all legal moves for the cell at the given position''' |
| 36 | PLAYER = self.board[row, col] |
| 37 | OPPONENT = Board.WHITE if PLAYER == Board.BLACK else Board.BLACK |
| 38 | legal_moves = list() |
| 39 | |
| 40 | # check for legal moves along the row of the cell |
| 41 | if col >= 2: |
| 42 | i = col - 1 |
| 43 | while i >= 0 and self.board[row, i] == OPPONENT: |
| 44 | i -= 1 |
| 45 | if (i != col - 1 and i >= 0) and self.board[row, i] == Board.EMPTY: |
| 46 | legal_moves.append((row, i)) |
| 47 | |
| 48 | if col <= 5: |
| 49 | i = col + 1 |
| 50 | while i < 8 and self.board[row, i] == OPPONENT: |
| 51 | i += 1 |
| 52 | if (i != col + 1 and i < 8) and self.board[row, i] == Board.EMPTY: |
| 53 | legal_moves.append((row, i)) |
| 54 | |
| 55 | # check for legal moves along the column of the cell |
| 56 | if row >= 2: |
| 57 | i = row - 1 |
| 58 | while i >= 0 and self.board[i, col] == OPPONENT: |
| 59 | i -= 1 |
| 60 | if (i != row - 1 and i >= 0) and self.board[i, col] == Board.EMPTY: |