【进阶实战】Lua笛卡尔积：祖玛教主挑战方案的组合枚举

local function enumerate(actor)
    for _, job in ipairs(JOBS) do
        for _, hour in ipairs(HOURS) do
            -- 漏了难度一层，24种只出12种
            table.insert(PLANS, job .. hour)
        end
    end
end

local function product(dims)
    local out = {{}}
    for d = 1, #dims do
        local nxt = {}
        for _, combo in ipairs(out) do
            for _, v in ipairs(dims[d]) do
                local copy = {unpack(combo)}
                copy[#copy + 1] = v
                nxt[#nxt + 1] = copy
            end
        end
        out = nxt                    -- 每维展开一轮
    end
    return out
end
sendmsg(actor, 1, "祖玛教主挑战方案共 "
    .. #product({JOBS, HOURS, LVLS}) .. " 种")