Lua双栈队列：两个栈实现的先进先出

local inStack, outStack = {}, {}
local function enqueue(v)
    table.insert(inStack, v)        -- 只进不出，出队时顺序反
end
local function dequeue()
    return table.remove(inStack, 1) -- 直接删表头，整体搬移
end

local inS, outS = {}, {}
local function dequeue()
    if #outS == 0 then
        while #inS > 0 do
            outS[#outS + 1] = table.remove(inS)   -- 倒栈反转顺序
        end
    end
    return table.remove(outS)
end
enqueue("金"); enqueue("银"); enqueue("铜")
sendmsg(actor, 1, "队列出队顺序 " .. dequeue()
    .. dequeue() .. dequeue())