【Lua实战】二叉堆实战：沙巴克攻城战输出排行的TopK统计

local heap, n = {}, 0
local function siftDown(i)
    while i * 2 <= n do
        local c = i * 2
        if c + 1 <= n and heap[c + 1].dmg < heap[c].dmg then c = c + 1 end
        if heap[i].dmg <= heap[c].dmg then break end
        heap[i], heap[c] = heap[c], heap[i]
        i = c
    end
end
local function push(rec)
    if n < 20 then
        n = n + 1
        heap[n] = rec
        local i = n
        while i > 1 and heap[i].dmg < heap[math.floor(i / 2)].dmg do
            local p = math.floor(i / 2)
            heap[i], heap[p] = heap[p], heap[i]
            i = p
        end
    elseif rec.dmg > heap[1].dmg then
        heap[1] = rec
        siftDown(1)
    end
end

local list = {}
for i = 1, n do list[i] = heap[i] end
table.sort(list, function(a, b) return a.dmg > b.dmg end)
for rank, rec in ipairs(list) do
    sendmail(rec.name, 0, "攻城战输出榜奖励", "本次攻沙排名：" .. rank, "功勋宝箱|1")
end