Langton's ant: Difference between revisions

=={{header|C Sharp|C#}}==

<lang C#>using System;

namespace LangtonAnt

{

public struct Point

{

public int X;

public int Y;

public Point(int x, int y)

{

X = x;

Y = y;

}

}

enum Direction

{

North, East, West, South

}

public class Langton

{

public readonly bool [,] IsBlack;

private Point _origin;

private Point _antPosition = new Point(0, 0);

public bool OutOfBounds { get; set;}

// I don't see any mention of what direction the ant is supposed to start out in

private Direction _antDirection = Direction.East;

private readonly Direction[] _leftTurn = new[] { Direction.West, Direction.North, Direction.South, Direction.East };

private readonly Direction[] _rightTurn = new[] { Direction.East, Direction.South, Direction.North, Direction.West };

private readonly int[] _xInc = new[] {0, 1, -1, 0};

private readonly int[] _yInc = new[] {1, 0, 0, -1};

public Langton(int width, int height, Point origin)

{

_origin = origin;

IsBlack = new bool[width, height];

OutOfBounds = false;

}

public Langton(int width, int height) : this(width, height, new Point(width / 2, height / 2)) {}

private void MoveAnt()

{

_antPosition.X += _xInc[(int)_antDirection];

_antPosition.Y += _yInc[(int)_antDirection];

}

public Point Step()

{

if (OutOfBounds)

{

throw new InvalidOperationException("Trying to step after ant is out of bounds");

}

Point ptCur = new Point(_antPosition.X + _origin.X, _antPosition.Y + _origin.Y);

bool leftTurn = IsBlack[ptCur.X, ptCur.Y];

int iDirection = (int) _antDirection;

_antDirection = leftTurn ? _leftTurn[iDirection] : _rightTurn[iDirection];

IsBlack[ptCur.X, ptCur.Y] = !IsBlack[ptCur.X, ptCur.Y];

MoveAnt();

ptCur = new Point(_antPosition.X + _origin.X, _antPosition.Y + _origin.Y);

OutOfBounds =

ptCur.X < 0 ||

ptCur.X >= IsBlack.GetUpperBound(0) ||

ptCur.Y < 0 ||

ptCur.Y >= IsBlack.GetUpperBound(1);

return _antPosition;

}

}

class Program

{

static void Main()

{

Langton ant = new Langton(100, 100);

while (!ant.OutOfBounds) ant.Step();

for (int iRow = 0; iRow < 100; iRow++)

{

for (int iCol = 0; iCol < 100; iCol++)

{

Console.Write(ant.IsBlack[iCol, iRow] ? "#" : " ");

}

Console.WriteLine();

}

Console.ReadKey();

}

}

}

</lang>

Output:

<pre>

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</pre>