-- 逆ピラミッド

local num = 8

local lnum=0
for j=0,2*num-1 do
  local nn = 0
  lnum =10000000
  for i = 1,num do
     y = ((num - j)^2) + (i^2) - (num ^ 2)
     y= math.abs(y)
     if y <= lnum then
       lnum = y
       nn = i
     end

  end

  for i = 1,num do
    turtle.up()
    if i == nn then
      turtle.placeDown()
    end
  end
  turtle.forward()
  for i = 1,num do
    turtle.down()
  end

end