-- 逆ピラミッド

local num = 16

local lnum=0

turtle.select(1)

for i = 1,10 do
  turtle.up()
end

-- ここから

for j =-1*num ,num do
  for i = -1*num,num do

      placeFlag = 0

      if i >=0 and j >= 0 then
        if (num)^2 <= (j+0.5)^2 + (i+0.5)^2 then
          if (num)^2 >= (j-0.5)^2 + (i-0.5)^2 then
    			  placeFlag = 1
          end
        end
      elseif i < 0 and j >= 0 then
        if (num)^2 <= (j+0.5)^2 + (i-0.5)^2 then
          if (num)^2 >= (j-0.5)^2 + (i+0.5)^2 then
    			  placeFlag = 1
          end
        end
      elseif i >= 0 and j < 0 then
        if (num)^2 <= (j-0.5)^2 + (i+0.5)^2 then
          if (num)^2 >= (j+0.5)^2 + (i-0.5)^2 then
    			  placeFlag = 1
          end
        end
      else
        if (num)^2 <= (j-0.5)^2 + (i-0.5)^2 then
          if (num)^2 >= (j+0.5)^2 + (i+0.5)^2 then
    			  placeFlag = 1
          end
        end

      end

      if placeFlag == 1 then
  			if turtle.getItemCount() == 0 then
  				selectNum = turtle.getSelectedSlot()
  				if selectNum == 16 then
  					selectNum = 0
  				end
  				turtle.select(selectNum+1)
  			end
        turtle.placeDown()
      end


  turtle.forward()
  end

  for i = -1*num,num do
    turtle.back()
  end

  turtle.turnRight()
  turtle.forward()
  turtle.turnLeft()

end