puzzle

local lights = {}
local function clear()
  term.clear()
  term.setCursorPos(1,1)
end
local function getNum(num)
  return math.floor((num+1)/2)
end
clear()
write "Enter Difficulty (minimum of 3): "
d = tonumber(read())
if d < 3 then
  error("Please Enter a number greater than 3")
end
for i=1, d*d do
  lights[i] = "false"
end
for i=1, d/3+d%3 do
  lights[math.random(d*d)] = "true"
end
clear()
function drawLights()
  for i=1, d do
    for a=1, d do
      term.setCursorPos((a*2)-1,i)
      if lights[(i*d)-(d-a)] == "false" then
        write("X")
      else
        write"O"
      end
    end
  end
end
drawLights()
local function getCoor()
  return (y*d)-(d-x)
end
local function setLights(lightNum)
  if lights[lightNum] == "true" then
    lights[lightNum] = "false"
  else
    lights[lightNum] = "true"
  end
end
while true do
  event, mouse, x, y = os.pullEvent("mouse_click")
  term.setCursorPos(1,7)
  x = getNum(x)
  setLights(getCoor())
  if y ~= 1 then
    setLights(getCoor()-d)
  end
  if y < d then
    setLights(getCoor()+d)
  end
  if x < d then
    setLights(getCoor()+1)
  end
  if x ~= 1 then
    setLights(getCoor()-1)
  end
  drawLights()
  local test = false
  for i=1, #lights do
    if lights[i] == "false" then
      test = true
    end
  end
  if test == false then
    break
  end
end
term.setTextColor(colors.yellow)
drawLights()
os.pullEvent()
clear()