[Feature Request] 讨论回复跳转优化

[langningchen]

检查项

• [X] 我已确认了XMOJ增强脚本已为最新版，且最新版未实现这一功能。
• [X] 我已在 Issues 页面 中搜索，确认了这一提案未被提交过。

描述

讨论回复提醒查看时应当直接跳转至相应的页面（如果是第二页的回复触发的提醒就跳转至第二页），而不是该讨论的第一页

原因

No response

[PythonSmall-Q]

errrrr好累

[langningchen]

@PythonSmall-Q 确实，我当时也很辛苦的

[PythonSmall-Q]

保持动力，客户至上

[langningchen]

当时我就是一个 Issue 没解决完又有一堆出来

[boomzero]

~保持动力~，客户至上

.

[boomzero]

Needs modifying the old db

[langningchen]

Needs modifying the old db

Why?

[boomzero]

Needs modifying the old db

Why?

@langningchen We only store postID

[boomzero]

Not replyID

[langningchen]

Emm...That seems bad. I forgot it.

PS: A have some problems about Competitive programming, may you help me?

[boomzero]

Emm...That seems bad. I forgot it.

PS: A have some problems about Competitive programming, may you help me?

What?

[boomzero]

In addition, we would appreciate it if you could check out https://github.com/XMOJ-Script-dev/XMOJ-Script/pull/599

[langningchen]

我太菜了，不会做……

[boomzero]

我太菜了，不会做……

Okay

[boomzero]

我太菜了，不会做……

Okay

保留六位小数?...

[boomzero]

考虑状压dp...

[langningchen]

我想到 DP 了，但是还是不会…… 我太菜了

[langningchen]

还有刚才 #599 是怎么回事？我没太明白……

[boomzero]

还有刚才 #599 是怎么回事？我没太明白……

review it, please

[boomzero]

我想到 DP 了，但是还是不会…… 我太菜了

和这道题有点像?

夏川的生日就要到了。作为夏川形式上的男朋友，季堂打算给夏川买一些生日礼物。

商店里一共有 $N$ 种礼物。夏川每得到一种礼物，就会获得相应喜悦值 $W_i$（每种礼物的喜悦值不能重复获得）。 每次，店员会按照一定的概率 $P_i$（或者不拿出礼物），将第 $i$ 种礼物拿出来。季堂每次都会将店员拿出来的礼物买下来。没有拿出来视为什么都没有买到，也算一次购买。

众所周知，白毛切开都是黑的。所以季堂希望最后夏川的喜悦值尽可能地高。

求夏川最后最大的喜悦值是多少，并求出使夏川得到这个喜悦值，季堂的期望购买次数。

[boomzero]

提供题解(我也很菜...) 可以发现，喜悦值其实是没有什么用的。因为喜悦值不会是负的，所以最大喜悦值一定就是所有物品喜悦值之和。

现在问题转化成：$n$ 种物品，每次按一定概率拿一件物品，问拿齐所有种类物品的期望次数是多少。

算法一（ $$10$$ 分）：

这是一个送分点，耐心手玩一下也能发现规律，直接计算就好了。

算法二（ $$30$$ 分）：

观察到 $N$ 比较小，可以考虑状压 DP。设二进制状态 $S$ 表示当前有哪些物品已经拿了，然后就可以转移了。具体来说：

$$fS=\sum\limits{i \notin S} (f_{S+{i}} \cdot Pi) + (1-\sum\limits{i \notin S} P_i) \cdot f_S + 1$$

然后可以列出方程组，用高斯消元求解。

时间复杂度： $$O((2^N)^3)$$

算法三（$100$ 分）：

我们观察到，$S+{i}$与 $S$ 只差一个 $i$，所以不需要高斯消元。

移项可得，

$$\sum\limits_{i \notin S} P_i \cdot fS = \sum\limits{i \notin S} (f_{S+{i}} \cdot P_i) + 1$$。

问题解决。时间复杂度： $$O(2^N \cdot N)$$

[langningchen]

好的，我看看

[boomzero]

Emm...That seems bad. I forgot it.

PS: A have some problems about Competitive programming, may you help me?

@langningchen So, impossible?

Is there a way to MODIFY a d1 database?

[boomzero]

Emm...That seems bad. I forgot it. PS: A have some problems about Competitive programming, may you help me?

@langningchen So, impossible?

Is there a way to MODIFY a d1 database?

Apparently this works

ALTER TABLE table_name
ADD COLUMN column_name column_type;

[langningchen]

Emm...That seems bad. I forgot it. PS: A have some problems about Competitive programming, may you help me?

@langningchen So, impossible? Is there a way to MODIFY a d1 database?

Apparently this works

ALTER TABLE table_name
ADD COLUMN column_name column_type;

It works? It does not work on my machine. My way is to create a new temp database with the correct structure and copy the data into it, then drop to orginal database and rename it back.

[boomzero]

Emm...That seems bad. I forgot it. PS: A have some problems about Competitive programming, may you help me?

@langningchen So, impossible? Is there a way to MODIFY a d1 database?

Apparently this works

ALTER TABLE table_name
ADD COLUMN column_name column_type;

It works? It does not work on my machine. My way is to create a new temp database with the correct structure and copy the data into it, then drop to orginal database and rename it back.

According to ChatGPT

[boomzero]

Your way is… messy

[boomzero]

Let me test in production