帮会旗帜争夺：帮会间的旗帜抢夺

local function grabFlag(actor, guild)
    local holder = getsysvar("flagHolder") or ""
    if holder == guild then
        sendmsg(actor, 1, "旗帜已在本帮手中")
        return
    end
    setsysvarex("flagHolder", guild)
    setsysvarex("flagTime", os.time())
    sendcentermsg(0, guild .. " 夺得旗帜！")
end

local function flagTick(guild)
    if getsysvar("flagHolder") ~= guild then return end
    setsysvarex("flagSec_" .. guild,
        (getsysvar("flagSec_" .. guild) or 0) + 1)
    if (getsysvar("flagSec_" .. guild) or 0) >= 300 then
        sendcentermsg(0, guild .. " 持旗满 300 秒获胜！")
    end
end