蛇形矩阵

#region 蛇形矩阵
        static void SnakeMatrix()
        {
            // 我们把它看做是一个回矩阵
            Console.WriteLine("请输入矩阵的行数");
            int n = Convert.ToInt32(Console.ReadLine());
            if ( 1 == n )
            {
                Console.WriteLine(1);
            }
            int rand = n >> 1;// n>>1 是圈数
            int[,] a = new int[n , n];
            int k = 0;
            int i = 0;
            int j = 0;

            for (i = 0; i < rand; ++i )
            {
                // right
                for (j = i; j < n - i; ++j)
                {
                    a[i, j] = ++k;
                }
                // bottom
                for (j = i + 1; j < n - i; ++j)
                {
                    a[j, n - i - 1] = ++k;
                }
                //left
                for (j = n - 2 - i; j >= i; j--)  //向左增长  
                {
                    a[n - 1 - i, j] = ++k;
                }
                //top
                for (j = n - 1 - 1 - i; j > i; j--)  //向上增长  
                {
                    a[j, i] = ++k;
                }
                if (0 != n % 2)//判断奇数
                {
                    a[n >> 1, n >> 1] = ++k;
                }
            }
            //顺时针
            Console.WriteLine("顺时针");
            for (i = 0; i < n; ++i)
            {
                for (j = 0; j < n; ++j)
                {
                    Console.Write( " {0,-4} " , a[i,j] ) ;
                }
                Console.WriteLine();
            }
            //逆时针
            Console.WriteLine("逆时针");
            for (i = 0; i < n; ++i)
            {
                for (j = 0; j < n; ++j)
                {
                    Console.Write(" {0,-4} " , a[j, i]);
                }
                Console.WriteLine();
            }
        }
        #endregion