Lua最小栈：双栈同步的常数取小

local stack = {}
local function push(v)
    stack[#stack + 1] = v
end
local function pop()
    local v = stack[#stack]
    stack[#stack] = nil
    return v
end

local data, mins = {}, {}
local function mpush(v)
    data[#data + 1] = v
    mins[#mins + 1] = math.min(v, mins[#mins] or v)
end
local function mpop()
    mins[#mins] = nil
    local v = data[#data]
    data[#data] = nil
    return v
end
local function getMin()
    return mins[#mins]
end
mpush(4); mpush(2); mpush(6); mpop()
local p = getplayerbyname("min01")
sendmsg(p, 1, "最小 " .. getMin())