Summary of the eighth ACM College Student Program Design Competition in Henan Province

Summary of the eighth ACM College Student Program Design Competition in Henan Province

There are so many slots in the province and day of the year.

But first, I 'd like to mention that I was so touched that I didn't eat in the dining room. The hotel's meals are more or less delicious than the school's restaurants ~~

The competition process is recorded as follows:

First of all, in the warm-up match on the first day, question B wanted to get a blood shot. As a result, he said a few more words, resulting in a one-minute delay. Then, wx and I thought that question A was too troublesome and handed it over to psq ~ 30 minutes later, the server crashed .. I saved the code and started to observe the surroundings ~ After that, I don't know when the server will be revived. I have handed in 1A. Then we realized that we didn't need to consider the nesting of parentheses, so the difficulty would be much lower in an instant. Then, during the test, it is found that the array size does not affect the meaning of science. There are no major discoveries.

Then the second day of the formal competition, first wx read question A, psq read question H, I read question B. Wx said that question A is the question of question A of yesterday. After reading question B, I found that the sample of question B is so strange that there is a space between the Mao numbers. After alignment, I found that the question is correct, then we directly think that the error is printed and tell wx water dfs that the entered space does not need to be considered. Then we decided to WA in 10 minutes. During the period, we found that someone had a question, which was called psq translation. I thought about it and printed question B and wrote it to G, it took 10 minutes to finish writing .. At this time, wx said that I am a god. Question B clearly stated that there are spaces in the input and forced to tell the wrong question. So I printed the G question and wx changed the B Question. After just a few minutes, I found that G questions were missed. I asked to skip the question, but I thought about it and finally changed the AC. At this time, it was found that several teams had passed question A and question F, and the three questions of the Nanyang Star team were currently the first. Then translate question F with psq, while wx conceived the framework of question. I found that I had won the first place after writing 1A in 10 minutes. Then psq thought about question C, and wx took over question A. I'll take A look at question D. Psq said that question C could be created and directly implemented. I said that question D is A minimum spanning tree. psq conceived the framework and I gave question A data. 2 minutes later, psq said that the D question was too big, and the question could be knocked out in 10 minutes. Then, he continued to think about the C question. In 72 minutes, all the testing data written by wx has been handed over to 1A, and the first step has been stabilized. Then psq took over 85 minutes of 1YD question. At the same time, I also came up with the creation and optimization of question C and continued to write C, while wx and I started to push questions E. E. At first, I thought that the epidemic prevention site could be started again. I wanted to write a framework in dp to help C. 144 minutes C question WA, check the code for 10 minutes, I don't know why it is wrong, I 've been out of the data plus test, and then I suddenly popped up the C question in 200 minutes after 144 minutes 1A, the 28-minute advantage is currently at the top. During this period, it was found that some people asked questions E. The epidemic prevention site could not be opened again, and the idea of dp was shattered. Next, I provided several ideas for psq's reference H, wx and I wanted E. Then psq found that he could not solve the problem, and reminded him to review the question. The result showed that the question must be a convex polygon, which instantly reduced the difficulty and began to work. However, wx and I have no idea about E-problems. wx indicates that we can see whether iterative search can be used. However, I find that it is similar to DLX to see if there are any ready-made templates. Then we found that we had no data for question H. At this time, we were unable to pass the sample through constant debugging of psq. During this period, wx knocked on question E and couldn't pass through the water. We were still the first. 296 minutes of successful debugging sample, directly submit 1Y scream (here seems to scare the giant beside T_T, expressed hope to understand :) the remaining 4 minutes to wx to see if E can be cut. At last, I still cannot access the accesskey. Sorry .. After the game, I asked if there were any 7 questions in each stadium. If I found no, I felt at ease. After three years, I successfully won the championship of the provincial light court!

Next, let's briefly explain:

Question

Simple string simulation.

Evaluate the relative molecular mass of the chemical formula following the equal sign of a chemical equation without the nested brackets. Simply record it.

Question B

Dfs, similar to hdu1241 ,.

0 represents the sea, 1 represents the land, the number of islands, and the area of the largest island. The island is extended in the 8 direction.

Question C

The most short circuit is a classic problem. It should be the original question.

For N one-way bus lines and M sites, find the minimum number of transfer times from 1 to M, and NO output is allowed.

For one-way lines, the value of one-way edge creation is 0 for each site, the value of two-way edge creation is 1 for other sites, and the shortest path from 1 to M is obtained.

Question D

Minimum Spanning Tree, Blue Bridge cup City Construction (previous questions)

Given the value of water source construction in each city in N cities, the price of pipelines between cities has been reached, and the minimum cost of water access in all cities has been asked.

Set up a virtual settlement point. All cities and their edges have the weight of the water source, and the minimum spanning tree is obtained.

Question E

I don't know the correct solution. I think it's DLX.

It is a pity that I have been planning to learn it before, but I think the provincial competition will not be so difficult. I just want to learn it after the provincial competition, which leads to the absence of AK.

Question F

The judgment point is in the Quadrant number.

G question

Poj2018 original question

Water problems, violence and security.

Question H

Calculation ry + shortest Circuit

When a line segment is set to a vertex, it uses a cross multiplication to determine the edge creation and runs the shortest path.

The following is a summary:

Okay. Let's talk about the problems. As the culprit of the team's only two WA projects, the most important thing is to carefully read the questions. Question B, question G, and question H are all due to the fact that the reading questions are not serious enough to take some time. The next step is that there are not enough knowledge points. If you have learned all the algorithms, there is no problem with AK. Although you have won the championship, it is a pity that you do not have an AK. Then, I hope that the younger students of the Light school will join the provincial competition and oil next year !!

Then it's time to vomit:

(1) question A is the original question of the warm-up match. Question B is similar to the original question, and question C is A classic question. Question D is the original question of the Blue Bridge cup, g.

(2) coupled with F's water problem, E and H are already super difficult. I feel that the provincial competition has become a pure competition for fast competition and careful competition. Throughout the entire audience, many teams did not have things to do in the last hour or even two hours. The subject discrimination was not high enough and it was impossible for many teams to complete the five hours.

(3) I heard that the server is unstable, and the next question is basically a semi-human question. In particular, the problem C is prone to severe mistakes.

(4) What about a good bonus T_T?

Finally, let's talk about my personal feelings. After listening to the teacher's explanations, I said that it was difficult to reduce the difficulty of the questions. In addition, many schools in Henan province could not win the Silver Prize in the semi-finals. In fact, I think there are a lot of problems with the quality of the provincial competition questions. Here we have to boast about the quality of the questions in our school competition, that is, no matter the contestants of the year, year, or year, there are algorithm questions, simulated questions, and perfect discrimination. Each team can be used for five hours. After all, this is the question of the golden medal team in the semi-finals. Therefore, I hope that the provincial division can be well aligned in this aspect. If it is weak, it is necessary to learn from and consult with others. If there is no bonus, it will at least improve the quality of the question. After all, this is a situation in Henan province, not only do some schools compete for Gold Prizes or anything, but they are not very harmonious between different schools. Of course, this is also because I don't want Henan province to be called a weak province in the future. Then, we hope to strengthen the rigor of the test questions. The data errors severely hit the players' mentality and time. As the organizer, for example, if the space is missing, this error is a low-level error. As long as there are two different codes, it can be completely tested. However, the provincial competition is also good. I just want to make everyone better and I don't know what to say .. That's it ..