【Lua实战】选择排序：装备评分榜的局部有序

-- 装备评分：攻击与持久加权
local bags = {
    {name = "裁决之杖", atk = 38, dur = 60},
    {name = "骨玉权杖", atk = 30, dur = 55},
    {name = "无极棍",   atk = 26, dur = 70},
}
local function scoreAll(list)
    local scored = {}
    for i = 1, #list do
        local s = list[i].atk * 0.6 + list[i].dur * 0.4
        scored[i] = {name = list[i].name, score = s}
    end
    return scored
end

-- 选择排序：取前五后提前结束
local player = class(actor)
local function topN(list, n)
    for i = 1, #list - 1 do
        if i > n then break end
        local best = i
        for j = i + 1, #list do
            if list[j].score > list[best].score then best = j end
        end
        list[i], list[best] = list[best], list[i]
    end
    return list
end
local ranked = topN(scoreAll(bags), 5)
local lines = {}
for i = 1, math.min(5, #ranked) do
    lines[i] = ranked[i].name .. " 评分 " .. string.format("%.1f", ranked[i].score)
end
sendmsg(player, 1, 0, "今日收购榜：" .. table.concat(lines, "；"))