Spiral Matrix——螺旋矩阵

        private static void PrintSpiral ()
        {
            int number = 3;

            int[,] spiralArr = Spiral(number);

            for (int i = 0; i < number; i++)
            {
                for (int j = 0; j < number; j++)
                {
                    Console.Write(spiralArr[i, j] + " ");
                }
                Console.Write("\n");
            }
        }

        static int[,] Spiral ( int number )
        {
            var position = new { x = -1, y = 0 };
            var directions = new[] { 
                new { x = 1, y = 0 },
                new { x = 0, y = 1 },
                new { x = -1, y = 0 },
                new { x = 0, y = -1 }
            };

            var sequence = (
                from n in Enumerable.Range(1, number)
                from o in Enumerable.Repeat(n, n != number ? 2 : 1)
                select o
            ).Reverse().ToList();

            var result = new int[number, number];

            int currentValue = 1;

            for (int i = 0; i < sequence.Count; i++)
            {
                var direction = directions[i % directions.Length];

                for (int j = 0; j < sequence[i]; j++)
                {
                    position = new
                    {
                        x = position.x + direction.x,
                        y = position.y + direction.y
                    };

                    result[position.y, position.x] = currentValue;
                    currentValue++;
                }
            }

            return result;
        }