69 lines
990 B
C#
69 lines
990 B
C#
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class Guard : IUpdate
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{
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private readonly Map _map;
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private readonly HashSet<(Vector2I, char)> _path = [];
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public char Direction { get; set; }
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public Vector2I Position { get; set; }
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public Guard(Map map)
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{
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_map = map;
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map.RegisterOnUpdate(this);
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}
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public bool? Step()
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{
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if (!_path.Add((Position, Direction)))
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{
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return null;
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}
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var test = NextPosition();
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if (!_map.IsValid(test))
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{
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return false;
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}
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else if (_map.IsOccupied(test))
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{
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Direction = Turn();
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}
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else
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{
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Position = test;
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}
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return true;
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}
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public void Update()
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{
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var tmpPosition = Position;
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if (Step() is not true)
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{
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_map.UnregisterOnUpdate(this);
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}
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else
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{
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_map.Move(tmpPosition, Position);
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}
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}
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private Vector2I NextPosition()
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{
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return Position + Program.ToVector(Direction);
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}
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private char Turn()
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{
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return Direction switch
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{
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'^' => '>',
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'>' => 'v',
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'v' => '<',
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'<' => '^',
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_ => throw new InvalidOperationException()
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};
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}
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}
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