Lua格雷码：相邻整数仅一位不同的编码

-- 直接把二进制原码当编码用，跳变时多位同翻
local code = string.format("%d", n)

local function gray(n)
    local bits, m = {}, math.floor(n / 2)
    local k = 0
    while k < 4 do
        local b1 = math.floor(n / 2 ^ k) % 2
        local b2 = math.floor(m / 2 ^ k) % 2
        table.insert(bits, (b1 + b2) % 2)
        k = k + 1
    end
    return table.concat(bits)
end
for i = 0, 7 do print(gray(i)) end
-- 输出 000,001,011,010,110,111,101,100