【高级技巧】近似TopN：热统计的流式估算

local samplePool = {}
local SAMPLE_RATE = 10
local function feedKill(actor, name)
    if math.random(1, SAMPLE_RATE) == 1 then
        actor = getplayerbyname(actor)
        local pool = samplePool
        pool[name] = (pool[name] or 0) + SAMPLE_RATE
    end
end
local function approxTopN(topN)
    local rows = {}
    for name, est in pairs(samplePool) do
        rows[#rows + 1] = { name = name, est = est }
    end
    table.sort(rows, function(a, b) return a.est > b.est end)
    local out = {}
    for i = 1, math.min(topN, #rows) do
        out[i] = rows[i]
    end
    return out
end

local function showHotBoard(actor)
    actor = getplayerbyname(actor)
    local top = approxTopN(10)
    for i, row in ipairs(top) do
        sendmsg(actor, 1, "热榜第" .. i .. "名 " .. row.name .. " 估算击杀 " .. row.est)
    end
end