Console.WriteLine("请输入一个整数");
            int count = Convert.ToInt32(Console.ReadLine());
            int[,] array = new int[count, count];
            int size = int.Parse(Math.Sqrt(array.Length).ToString());
            int row = 0, column = 0, n = 1, num = 1;
            bool bo = true;
            while (bo)
            {
                row = column = n - 1;
                while (column <= size - n)
                {
                    if (array[row, column] != 0)
                        if (array[row, ++column] != 0)
                        {
                            bo = false;
                            break;
                        }
                    array[row, column] = num++;
                    column++;
                }
                if (!bo) break;
                column--;
                while (row <= size - n)
                {
                    if (array[row, column] != 0)
                        if (array[++row, column] != 0 || row == size-1)
                        {
                            bo = false;
                            break;
                        }
                    array[row, column] = num++;
                    row++;
                }
                if (!bo) break;
                row--;
                while (row == column)
                {
                    row--;
                    column--;
                    if (array[row, column] != 0)
                        break;
                    array[row, column] = num++;
                }
                n++;
            }            

            for (int i = 0; i < size; i++)
            {
                for (int j = 0; j < size; j++)
                {
                    Console.Write(array[i, j].ToString() + "  ");
                }
                Console.WriteLine();
            }
            Console.Read();

------解决方案--------------------
C# code

            int inputNumber = 6; //输入参数
            int row = Convert.ToInt32(Math.Sqrt(inputNumber * 2 + 1 / 4) - 1 / 2);
            int[,] array = new int[row, row];
            int columnIndex = -1;
            int rowIndex = 0;

            int mode=0; //0 行走， 1 斜走 ， 2 列走

            for (int i=1; i<=inputNumber  ; i++  )
            {
                switch (mode)
                {
                    case 0:
                        
                        columnIndex++;
                       
                        if ( columnIndex <row && array[rowIndex, columnIndex] == 0)
                        {
                            array[rowIndex, columnIndex] = i;
                        }
                        else
                        {
                            i--;
                            columnIndex--;
                            mode = 1;
                        }
                        break;
                    case 1:
                        rowIndex++;
                        columnIndex--;
                        if (rowIndex <row && columnIndex >=0 && array[rowIndex, columnIndex] == 0 )
                        {
                            array[rowIndex, columnIndex] =i;
                        }
                        else
                        {
                            i--;
                            rowIndex--;
                            columnIndex++;
                            mode = 2;
                        }
                        break;