SpaceshipFateCSharp

struct Point
{
    public Point(int x, int y) { X = x; Y = y; }
    public int X, Y;
}

class OrbitException : Exception { }
class CrushException : OrbitException { }

List<Point> planets = new List<Point>();
List<string> history = new List<string>();
Point rocket, velocity, universeSize;

public void Main()
{
    var i = 0;
    for (var line = Console.ReadLine(); line != ""; line = Console.ReadLine())
    {
        universeSize.X = line.Select((c, j) => CreateObject(c, i, j)).Count();
        i++;
    }

    universeSize.Y = i;

    var x = new Action<string>(Console.WriteLine);

    try
    {
        while (true)
        {
            ApplyGravity();
            Move();
        }
    }
    catch (CrushException) { x("crush"); }
    catch (OrbitException) { x("orbit"); }
    catch { x("escape"); }
}

Point CreateObject(char c, int i, int j)
{
    if (c == '@')
        planets.Add(new Point(j, i));
    else if (c != '.')
    {
        rocket = new Point(j, i);
        velocity = (c == 'v' ? new Point(0, 1) : c == '<' ? new Point(-1, 0) : c == '^' ? new Point(0, -1) : new Point(1, 0));
    }

    return universeSize;
}

private void ApplyGravity()
{
    planets.ForEach(planet =>
    {
        var dx = planet.X - rocket.X;
        var dy = planet.Y - rocket.Y;

        if (dx < 2 && dx > -2 && dy < 2 && dy > -2)
        {
            velocity.X += dx; velocity.Y += dy;
        }
    });
}

private void Move()
{
    // check if orbit; save current context
    var context = string.Join(".", rocket.X, rocket.Y, velocity.X, velocity.Y);
    if (history.Contains(context))
        throw new OrbitException();

    history.Add(context);

    // colision check
    var position = new Point(rocket.X, rocket.Y);

    var k = new[] { velocity.X, velocity.Y };
    var min = k.Min();
    var max = k.Max();

    for (int i = 1; i <= max; i++)
    {
        if ((i * min) % max == 0)
        {
            var p1 = new Point(
                position.X + (velocity.X == max ? i : i * min / max),
                position.Y + (velocity.Y == max ? i : i * min / max));

            if (planets.Contains(p1))
                throw new CrushException();
        }
    }

    // apply move
    rocket.X += velocity.X;
    rocket.Y += velocity.Y;

    // bounds check
    if (rocket.X < 0 || rocket.X >= universeSize.X || rocket.Y < 0 || rocket.Y >= universeSize.Y)
        throw new Exception(); // using plain Exception for 'escape' condition
}