双人双修：同屏共修的经验加成

local function duoBonus(actor, mate)
    local p = getplayerbyname(mate)
    if p == nil then return 0 end
    local isFriend = string.find(
        getplayvar(p, "friendList") or "",
        getplayvar(actor, "NAME"), 1, true) ~= nil
    local sameMap = getplayvar(p, "MAP")
        == getplayvar(actor, "MAP")
    if isFriend and sameMap then
        return 50   -- 封顶 50% 加成
    end
    return 0
end

local function grantExp(actor, base, mate)
    local bonus = duoBonus(actor, mate)
    local exp = math.floor(base * (100 + bonus) / 100)
    sendmsg(actor, 1, "获得经验 " .. exp
        .. (bonus > 0 and "（双修加成）" or ""))
end