蜗牛算法

class Program
    {
        static void Main(string[] args)
        {
            int num=0;
            Console.WriteLine("请输入矩阵的长度：");
            string getKeys= Console.ReadLine();
            int.TryParse(getKeys, out num); //输入数组长度
            int[,] dataArray =new int[num,num]; 
            int y=0;  //设置初始值，线一开始位置 坐标 x,y
            int x=0;  
            int number=1;   //蜗牛的起点

            if (num % 2 != 0)//
            {
                dataArray[num / 2, num / 2] = num * num;
            }
           
            First(num, dataArray,  y,  x,  number);
           
            PrintDataArray(num, dataArray);
            Console.ReadKey();
        }

        private static int First(int num, int[,] dataArray,  int y,  int x, int number)
        {
            
            int startX = x;
            int startY = y;
            #region 实现蜗牛的围墙
            while (y < num - 1)
            {
                dataArray[startX, y] = number;
                number++;
                y++;
            }
            while (x < num - 1)
            {
                dataArray[x, y] = number;
                number++;
                x++;
            }

            while (y > startX)
            {

                dataArray[x, y] = number;
                number++;
                y--;
            }
            while (x > y)
            {
                dataArray[x, y] = number;
                number++;
                x--;
            } 
            #endregion
            num -= 1;
            startX++;
            startY++;
            if (num > 2)
            {
                return First(num, dataArray, startY, startX, number);
            }
            else
            {
                return 0;
            }
        }

        private static void PrintDataArray(int num, int[,] dataArray)
        {
            for (int i = 0; i < num; i++)
            {
                for (int j = 0; j < num; j++)
                {
                    Console.Write(dataArray[i, j].ToString("#0#") + " ");
                }
                Console.WriteLine();
            }
        }
    }