CC Turtle Quarry

function square(size)
	n = 0

	size = size - 1

	for i = 0,size,1 do

		for i = 0,size,1 do
			turtle.digDown()
			turtle.forward()
		end

		n = n + 1

		if turtle.detect() then
			addM = false
		else
			addM = true
		end

		if n%2 == 0 then
			turtle.turnLeft()
			turtle.forward()
			turtle.turnLeft()
			if addM then
				turtle.forward()
			end
		else
			turtle.turnRight()
			turtle.forward()
			turtle.turnRight()
			if addM then
				turtle.forward()
			end
		end
	end

	if n%2 == 0 then
		turtle.turnLeft()
		for i = 0,size,1 do
			turtle.forward()
		end
		turtle.turnRight()
		for i = 0,size-1,1 do
			turtle.forward()
		end
		turtle.turnRight()
		turtle.turnRight()
	else
		turtle.turnRight()
		for i = 0,size,1 do
			turtle.forward()
		end
		turtle.turnLeft()
		for i = 0,size-1,1 do
			turtle.forward()
		end
		turtle.turnLeft()
		turtle.turnLeft()
	end
end

while true do
	square(3)
	turtle.down()
	sleep(0)
end