38 lines
1.2 KiB
Python
38 lines
1.2 KiB
Python
from tugo.gotypes import Point
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__all__ = [
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'is_point_an_eye',
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]
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def is_point_an_eye(board, point, color):
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if board.get(point) is not None:
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return False
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# All adjacent points must contain friendly stones.
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for neighbor in board.neighbors(point):
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neighbor_color = board.get(neighbor)
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if neighbor_color != color:
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return False
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# We must control 3 out of 4 corners if the point is in the middle
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# of the board; on the edge we must control all corners.
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friendly_corners = 0
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off_board_corners = 0
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corners = [
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Point(point.row - 1, point.col - 1),
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Point(point.row - 1, point.col + 1),
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Point(point.row + 1, point.col - 1),
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Point(point.row + 1, point.col + 1),
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]
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for corner in corners:
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if board.is_on_grid(corner):
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corner_color = board.get(corner)
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if corner_color == color:
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friendly_corners += 1
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else:
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off_board_corners += 1
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if off_board_corners > 0:
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# Point is on the edge or corner.
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return off_board_corners + friendly_corners == 4
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# Point is in the middle.
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return friendly_corners >= 3
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