...

P: 我现在怎么枚举啊？

F:我现在可以知道，最左边和最右边，的值

P: 什么叫枚举啊？

F:不是你看，什么东西只会出现一个

P：最大值啊

F:对称的，对称的，只会出现一次对吧。但是当中有一个，嗯……

P:我觉得……欸，好像很有道理

F:对吧，然后你看他，你看这个数量，你就可以首先判断出来首先他是抠掉了一个，出现两次的还是出现一次的

P:就是……如果我们……哦！

F:如果他是抠掉两次的那个你就枚举是抠掉的哪一个，然后来细心地验证他

P:这能枚举吗？（时间复杂度能通过这个问题吗？）

F:n个啊！

P:有n^2个啊？

F:不……你会有……n/2个出现过一个的

P: How do I enumerate now?

F: You now know, the leftmost and rightmost, values.

P: What do you mean by enumerate?

F: No, you can see that only one of something will appear.

P: The maximum value?

F:its symmetric, symmetric. It only occurs once, right? But among them there is one ... uh...

[Voice of unknown person]:That's what it feels like.

P:I think ...... hey, it seems to make sense

F:Right, and then you look at it, you look at its count, you can first determine first of all whether he is removed once... i mean, appear twice or appear once

P:That's ...... if we ...... I got it!

F:If he is the one who removed twice you enumerate which one is removed and then come to verify him carefully

P:Can this be enumerated? (Will the time complexity pass this problem?)

F:There are n of them!

P:Are you sure? there are n^2 of them, aren't there?

F:No ...... you'll have ......n/2 one with only one occurrence.

……

P:就是多出来是端点……就首先我们是assume他是删了恰好那个，所以说——这个是被删掉的——然后所以说刀（删掉）的位置是这些，就这个肯定是有的，而且他是一一抵消后，最大的那个，然后你拿全局的一减，就得到了，这个是多少对吧

F:也不是全局一减。我这里画的不太对。就他还有刀另外半边的所有的。对吧

P:对

F:那无论如何，你可以找到一个最大的……

P:我知道啊？你已经知道全局是多少了……

F:你看，那样子的话我可以

P:I mean, the extra ones is the endpoint ...... on first of all, we assume he is deleting exactly that, —— this is deleted —— then so that the killed (deleted) position is these, on this is definitely there, and he is one by one after canceling out, the biggest one, and then you take the global one and subtract it, and you get, this is how much, right.

F: It's not a global subtraction either. I'm not drawing it right here. It's just that he has to delete all of the other half. Right?

P:Right.

F:Then anyway, you can find a maximized ......

P:I know it. You already know what its global value is ......

F:Look, that way then I can...

F:然后然后给它除以2变成变成原题目当中121

P:你对了，但是但是我怎么没有跟上，你的思路……不是这个1和7，你怎么……怎么就这样了呢，

F:就你就你找到这个一就行了，你找到这个这当中最小的

P:为什么是最小啊，不应该是最小吧，为什么是最小

F:啊啊，呸呸你找你找到最大的嗯，然后用全局减最大也可以就最大，最大的也可以，

P:那你怎么知道全局……哦

F:不你你有，你有最大的也可以，你就拿你就拿这个最大你知道最大，它一定是一个边缘到这个较远端的这个搁这个刀子（删除的地方）上对吧，

P:对对对，

F:那么这个减减，减，减，减减减，然后减到什么时候变成零了

P:没错，没错

F:变成成零的位置，就是他刀子在的位置

P:没错，没错

F:然后刀子左边和右边捏起来就搞定了，

P:哎呀！……啊，对对对对对，但是但是，但是为什么（你画的）这个7、7、6、6、5、5、1、1正好是偶数个，然后让他删掉一半呢，

F:因为你这个你这个你……你什么东西是多出来的，是你以刀子为端点的对吧，是你两边你，你2个端点都是刀子的，这个你不存在，所以呢，你只有一个端点是刀子，一个端点，是原来的东西……

P:等一下，等一下你你，你怎么你怎么敢敢相信，他们奇偶性相同呢，呃等一下呃呃，

F:就他要么……要么他的刀子是左边的刀子作为端点，要么是右边的刀子作为端点，他同一个区间，他这么来一下，他还得对称来一下，所以肯定是……所以同样的位置肯定是偶数个，

P:你先别急。啊，呃，呃，不是我操

[Unknown Person]

P:不要不是我看一下啊。但是……，多……多的是哪个来着呃，是是六对吧，六是多出来的，那个对吧，这这这那为什么为什么六……

F:那什么多出来的？

P:这个6

F:不，这是之前的，这……这个扔了，我这是之前的，没，这没有，这没有

P:嗯

F:啊，呸这个是这个是你，有的，这个是你有

P:对啊我有，但是明明六是多出来的一个，那那那那那怎么……

F:什么叫六是多出来一个？六多出来2个！

F:and then divide it by 2 to make it 1,2,1 in the original question.

P:You're right, but but but.. I did not keep up with your thought process ...... no, why this 1 and 7, heck, how you ...... how it's just like that.

F: Well, you just need to find the one, the smallest one of these.

P: Why is it the smallest one? It shouldn't be the smallest, why is it the smallest?

F: Ah, ah, no, no, you find the largest one instead, and then use the global minus the the largest. So finding the largest can also be ok.

P:then how do you know the global ...... oh

F:no you ... you have the largest one, that's fine, you just take the largest one, you know the largest one, it must be an edge point further to the cut point (deletion).

F: Then subtract, subtract, subtract until it reaches zero.

P: That's right, that's right.

F: When it reaches zero, that's where the deletion is.

P: That's right, that's right.

F: Then pinch the left and right sides of the cut, and the problem is done.

P: Oh! ... oh, right, right, right, right, but why are there exactly even counts of 7, 7, 6, 6, 5, 5, 1, 1, and then you remove half of them?

F: Because the extra part is defined from the knife as the endpoint, right? It's between the two endpoints, both are on the knife, this doesn't exist, so you only have one endpoint that's the knife, and the other endpoint is the original stuff...

P: Wait, wait, how can you be sure that their parity matches, wait a minute...

F: The deletion either uses the left part as the endpoint or the right as the endpoint. Within the same range, it needs to be symmetrical, so the positions must match, and the parity will be even.

P: Wait, don't be hasty, ah, ah, uh, it's not, I…

[Unknown Person]

P: What? Let me see... But, which part is extra... oh, it's the number 6, right? 6 is the extra part, right, then why is 6...

F: What do you mean by extra?

P: This 6.

F: No, this was my illustration before, this… this part can be ignored, this part wasn't there.

P: Mm.

F: Ah, no, this is what you had, this is what you have.

P:Yeah I have, but obviously number 6 have an extra one remaining, that that that that that that how ......

F:What do you mean 6 has 1 remaining? There are two extra sixes!

……

(P opens dev-cpp)

P:等下我去洗澡

F:别洗了，快做。我去洗。洗漱用品呢

P:怎么？

F:那我帮你洗，

P:什么叫你帮我洗……，

F:我帮你洗，

P:……

F:那么别吵了，快写，快把这题写了，除非你不想上大分……你先看一下多少人过了

P:一个不是一个，

F:那是刚刚只有一个，

P:是不是啊，我爆了，我得……

F:那对的要死

P:哎，你先没急，哎呦，我知道你对的要死，但是你别急

F:那给我洗，

P:Ok ok，哎，（变量）m 是这个……

F:没有m，哪里有m

P:嗯，我等一下，等一下

F:是cin>>T，哦，solver（这个函数里，那应该是）cin>>N

P:(m=)n*(n-1)/2，然后我要读入m-1个数

F:对

P:嗯，然后把那个开一个multiset，呃我开一个multiset，

F:你要开一个map来当计数器

P:都行啊，都一样吧

F:肯定是map当计数器更快呀，

P:真假的？

F:真的

P:嗯……

F:map你这样用的？

P:哎呀，你不要哎呀，我现在脑壳不太好……ok，然后我们要看有哪些是出现奇数次，对吧，

F:对。你看你这不就需要计数器吗，你multiset的不得搞（写）到地老天荒去

P:哦，哦，你是我爹……k，k是啥。等下，我知道了。cnt

F:嗯

P: Wait, I'm going to take a shower.

F: Don't shower yet, hurry up and write its code. I'll wash up. Where's your toiletries?

P: What?

F: Let me wash for you.

P: What do you mean, let me wash for you...?

F: I'll help you wash.

P: ...

F: Stop arguing, hurry up and write this problem, unless you don't want high performance... check how many people passed.

P: One, not one,

F: There was only one.

P: It's over.

F: But my solution must be definitely correct.

P: Wait, don't be hasty, oh my, I know you’re right, but don’t be hasty.

F: Let me do the laundry.

P: Ok, ok, hey, the variable m is...

F: There is no m, none of your m in the problem.

P: Mm, wait, wait, what the...

F: It's cin >> T, oh, solver (in this function, it should be) cin >> N.

P: (m=) n*(n-1)/2, then I need to read m-1 numbers.

F: Correct.

P: Mm, then write a multiset, uh, I'll write a multiset.

F: You should write a map as a counter.

P: Both are fine, right?

F: A map as a counter is definitely faster.

P: Really?

F: Really.

P: Mm...

F: How can you using the map like that?

P: Oh no, don't oh no me, my brain isn't good right now... ok, then we need to see which ones appear an odd number of times, right?

F: Yes. You see, you need a counter, don't you need to complete your code with multiset for ages?

P: Oh, oh, you're my dad (Used to express thank in Chinese)... k, what is k. Wait, I know. It's cnt.

F: Mm.

……

P: 今天那一个题确实难写。哎呀，没有你真的过不了D好吧

F: 是吧

F:我告诉你啊，这个视频要上传啊，就是那一段也会上传，但愿审核不会发现啊

P: So that problem today is really hard to write. Without you, I wouldn't have solved D.

F: I think so.

P: I remind you that this video is to be uploaded, with that section, wish it not be censored.

F:肯定要完了，那别人说你场外援助举报你怎么办

P:不care，我场外援助又不是第一次了

F:不是第一次吗原来？

F: What if someone report you for your communicating with other people for help.

P: I don't care. I've asked for help for more than once.

F: Really? So more than once?

P:没事没事，再怎么说E也是我自己做的，那个……

F:嗯，是

P:D去掉。好吧，D去掉可能也没有很强啊

P: It's okay, it's okay. I solved E myself anyway. Uh...

F: I think so.

P: without D. Well, without D my performance is probably not very strong.