【高级技巧】Lua桶计数：裁决之杖库存等级的分布统计

table.sort(items, function(a, b)
    return a.lv < b.lv end)          -- 5000件全排只为看分布
for _, it in ipairs(items) do countLv(it.lv) end

-- 裁决之杖库存按等级分布
local function byLevel(actor, items)
    local bucket = {}
    for _, it in ipairs(items) do
        local lv = it.lv
        bucket[lv] = (bucket[lv] or 0) + 1   -- 值作桶号累加
    end
    for lv = 1, 200 do
        if bucket[lv] then
            sendmsg(actor, 1, lv .. "级 " .. bucket[lv] .. " 件")
        end
    end
end