【高级技巧】Lua分组Top-K：烈火剑法每职业前3的榜中榜

table.sort(all, function(a, b) return a.score > b.score end)
-- 全排后再按职业各截前3，2000人白排大头

local function top3ByJob(all)
    local board = {}
    for _, p in ipairs(all) do
        local b = board[p.job]
        if not b then
            b = {p}; board[p.job] = b
        elseif #b < 3 or p.score > b[3].score then
            b[#b + 1] = p
            table.sort(b, function(x, y)
                return x.score > y.score end)
            if #b > 3 then table.remove(b) end   -- 裁掉榜外
        end
    end
    return board
end
sendmsg(actor, 1, "烈火剑法战士组头名 "
    .. top3ByJob(ALL)["战士"][1].score)