A complete failure, a serious blow...

Third Sichuan University student ACM/ICPC program design competition,

The first and last provincial competition,

This is a fiasco...

The loss was so thorough.

First of all, we cannot compete with the strong teams of the Greater China and the Greater China,

The team's cooperation and mentality are also vulnerable.

If no problem is found or solved,

Even if two months of summer work hard,

There will be another cup in the semi-finals.

Always comfort yourself with the Weak School,

But Zhejiang Normal University won the gold medal in final,

I was shocked.

In addition to the maxcompute service,

West minxi petroleum West Huadu won the silver medal.

Although our school has two separate houses,

The School of Science and Technology has been under our suppression,

Until this time we all rushed to the street,

They finally spoke up.

However, the main force of xipetroleum is actually from the School of Economics and Management...

Worse than our school,

But better than us.

What is missing in our school?

 

This failure is not a weakness,

It is more about mentality.

During the warm-up match, a problem occurred while reading the question,

I cannot understand the question,

Finally, I gave up and did not go further.

At the beginning of the official competition,

It showed a tense mentality,

I said don't be nervous. Reading questions a few seconds earlier has no impact.

Then I logged on to my account and found that the password was the password for the warm-up match yesterday,

The password is incorrect...

Many teams have incorrect passwords,

I don't know how Neusoft college works.

Volunteers collect account information,

Will return the password information.

We started to look at the subject based on the planned division of labor,

Neusoft (the organizer) is really economical. There is only one copy of the question and it is still dual-sided,

Reading questions is inconvenient.

When I was reading questions, I felt very uneasy,

I just want to find a simple question.

In the face of a lot of English, you only have to read questions with a hard head,

Let's look at question E first, which is a search question similar to 8 digital.

Let's look at question F. I found the question water,

This is very exciting,

So I quickly knocked on the code, and then I ran out of it,

I thought about a few more data.

Question F is how many good morning substrings can be found after a string is reordered,

A good moring requires two 'G', three '0', one 'D', one 'M', one 'R', and one 'I', 2 'n', 1 space,

I directly count the number of letters, find the maximum number of words that each letter contains, and finally find the minimum value.

At this time, the Volunteers sent the password,

I think there are several teams on the board that have passed question F,

Hesitated and submitted question F,

Return WA...

I am confused and feel that I have not understood the question correctly,

How can this problem be wrong...

Look at the board and find that attempt is regarded as AC,

It turns out that there are few AC,

It seems that there are some traps, or the meaning is wrong.

Dearway says question A is A question, so I have to knock on the code.

Mi and I studied question F again, and I felt nothing wrong.

Dearway told me not to worry about question F first. Let's take A look at question.

When I read question A, I may have been unable to read question F carefully,

I directly look at the example. I guess the question is to give a number to determine whether it is within the given six intervals.

There is an accurate ratio constant which does not know what it is,

Dearway cannot write the code. For example, he asked me whether accurate ratio is multiplication or division,

I don't know. I think his code multiply the input number by accurate ratio and then judge the interval,

At this time, I saw the board and found that we had a newbie team in the freshman year and sophomore year...

I can't pass the example, but I still cannot pass the Division. I think there are 2.51 accurate ratio, and there is no way to pass the division.

So I suspect that accurate ratio is not used in this way. I took a closer look and found that the right side of the interval divided by the left side is about 2.51,

I'm speechless. I don't know how to read questions...

Accurate ratio is useless.

Finally, the question is AC, and now it is 36 points in the competition.

The team that saw several questions on the board was over question F, so dearway said that he would write questions F again,

The idea is the same as that of me. It must have been WA and I have submitted it...

So everyone began to suspect that the meaning of the question was wrong. All kinds of YY started, and the afternoon of the Cup officially started...

In the middle, mi said that question J was the original question. I thought it was true after reading the film,

The question is written by dearway. Let him see it,

He does not have the same question. He will wait for a while.

The original question is to give a 01 ring, and find the minimum number of switching steps (any switching) to change 01 to continuous,

This question can only be exchanged between adjacent locations.

After reading the K questions, I can return n 64-digit digits. I can reverse some of them and add the and, or, and xor operators to minimize the final result.

I thought for a moment, there is no idea.

In the middle, I went to the toilet and saw that our school was full of one question. There were already three questions in the family planning project...

Mi said that question C is relatively simple. I started to write code for a long time.

I think I should be a DP and start the YY transfer equation. At this time, dearway asked me to help mi look at question C,

Question C is to judge whether it is Heap or bst for a Complete Binary Tree. I directly wrote the code on the paper.

The more I write mi, the more chaotic it is. I only need to write it. I have to knock out the code on the paper and submit it to WA,

Then we can see that we haven't even created a group of data...

I changed WA several times before thinking about the question...

I have been studying with mi for a long time what is a Complete Binary Tree, Heap, BST,

Mi is responsible for the data structure. I don't know much about the data structure.

Later, I thought that I should not write the judgment in a DFS. Based on the nature of BST, I can traverse it and determine whether it is ordered,

Then, when Heap is determined, another WA...

Then I thought of another situation where Both Heap and BST were not taken into account. when there were two nodes, the two nodes had the same value as Heap; otherwise, the two nodes had the same value as Heap.

I finally AC this question after WA n times...

When I came back, I thought that it was very easy to directly write four DFS with the same structure to determine the maximum heap, the minimum heap, and the two BST types.

Then mi and dearway started the meaning of all kinds of yy f questions, all kinds of chaos, totally deviated from the question, and I was numb when I looked at the returned WA again and again.

In the middle, I went to the toilet and saw three questions in our lab's sophomore team, and the four questions in the family planning team next to them were suddenly disheartened...

I think question B has a thought that flashed through-search, and I immediately reject it. It feels too violent.

Then I thought of the shortest circuit. I wrote the code on the paper, which is troublesome to create a graph.

When I saw several teams passing through, I thought I could be able to access the AC right away.

It wasn't until the last half an hour that I got bored with question F that I had the opportunity to tap into question B's code (I Asked Question B in the middle, and I said the code was a little long and asked them to write it first)

I found a small problem when I typed the B-question code. I asked them to write the F-question. I went to the next step and used the sample to create a diagram. I printed the code and found it wrong,

The last few minor errors are found. After correction, the system submits and returns the TLE...

After studying the questions carefully, I found that the 64-digit change or TLE was used. Has the complexity of SPFA reached the worst O (nm )?

Then the competition is over ......

We have no face for Jiangdong's elders.

 

Why did we get a cup of cake after the wireless sensor network...

He asked us how to write question B. I said it was the shortest path,

He said that Liao hongshu (the author) said that it was DP-added line segment tree optimization...

Later, the sophomore team said it was written by the BFS optimized by the priority queue, but the BFS used by the Division was AC,

Ask me why I don't need to search and write...

Later I thought that it wasn't the SPFA time-out, but the time-out when I created the image. I had thought about the second point when I created the image. I felt that it was useless without much influence,

Now I think that the time-out is not required for the second part. It may be O (n ^ 2) after creating a graph, n = 10 ^ 5.

And f I initially understood the correct meaning of the question, but 'G' is not decided g/2 good morning, But g-1 a good morning,

Because the last 'G' of the last good morning can be regarded as the first 'G' of the next good morning '.

The chaos behind us is completely SB behavior...

This question has plagued us for four hours!

 

At the beginning, I thought that I could win the first prize for the four questions of the family planning subject. I heard that Neusoft's post-titled AC1 won the first prize with five questions,

At that time, I was shocked and seriously worshipped Neusoft College !!!

 

This failure is totally a matter of mentality and cooperation.

There is definitely no return if you don't pay,

Even if you pay, you may not be rewarded.

If we can be as calm as a warm-up match, we will certainly not have such a cup,

Even a person won't have such a cup.

Three people in one team, but only one computer keyboard.

The three ideas can be complementary, but may also affect each other.

A person's nervousness may lead to team tension.

The pressure of a team, the pressure to win the prize...

I never wanted to be a so-called one-team player. I went to the warm-up match to compete with the second team for the position of the six-team member, and finally got caught up again,

The competition is based on the registration order of the first and second teams, but dearway has always considered that the second team is better than the second team,

The competition said there were two more questions than they did. In fact, there was already a precedent in front of them,

But this time they were completely defeated, defeated by the Family Planning Department, and defeated by themselves...

In fact, our team is not necessarily better than them. We are only qualified to be old, so we have always lived in a team in the lab.

Watashi, the world champion, wrote in his blog: last year, I chose three self-downgrading teams due to my lack of ability.

How can we be arrogant if the world champion is still so arrogant?

There are only two people in our team, but there are still many problems,

If these problems are not solved, the semi-finals will have another cup in a few months,

Efforts over the past few years will be wasted (though not over the past two years ).

I used to read an article about training sessions over the past 20 days. I stayed in the lab every day for instant noodles and finally received the prize,

I often think that this will not happen if I come up with my postgraduate students.

This failure gave me the idea of retiring,

The last opportunity, preparations for the last few months, if you can achieve the desired results, you can try again,

Otherwise, it would be better...

But how can I know the final result without trying?

 

I have already engaged in DP and ended in failure (I am afraid to see the DP question later... Sometimes I want to do some DP questions ).

Graph theory will be followed by a bit of foundation, and the network stream model is not proficient yet.

After A search, it will be DFS, BFS, and.

There is no data structure at all, but I still want to learn it, but they have all done it.

There are also number theory + combined mathematics and computational ry. First, let's see if there is any feeling before deciding which one to learn.

Greedy depends mainly on intelligence.

Game theory needs to be learned.

Simulate and compare to exercise code capabilities.

Now it seems that the only thing we are good at is the water questions we used to have. Now we are not very good at it...

 

Summer schedule:

Starting from July 10, the competition mainly involved individual competitions synchronized with Sichuan TV University.

From August to August 20, the competition was dominated by various online teams.

 

It seems that we should be proficient in graph theory and search before March,

Then we will select number theory or computational ry.

Greedy, game, simulation, and so on.

 

In addition, you must be familiar with Ubuntu and Eclipse.

 

Blog by watashi, world champion: http://watashi.ws/blog/2044/icpc-2011-orlando-wf/