Summary of urgent need for RP _ Zhejiang Sci-Tech Invitational Competition

The first few of the Provincial Division silver awards and the first few of the zstu invitational competitions are bronze awards. RP is completely unprotected. Brother is destined to be a tragedy, alas.

Remember the course of the competition, the first three in LJ, the third in the middle, and the last four in tracyzhu. Question D is about Dota. Check whether the arrow of the Female priest of the month hits the target. Specifically, if a source point and a vector are given, check whether the polygon hit by the ray is distorted, I feel that I can write, but I am not afraid to write it. I have always seldom written questions about computational geometry. After all, the accuracy problem has been quite tangled. At this time, LJ said that question a is to find the minimum spanning tree when a vertex can be removed, and then I went up and knocked it out in more than 20 minutes, the sample is not correct. debug it. 1 y in a few minutes. Then I want to write d. tracyzhu said that he saw a more watery one. In other words, he wrote H, I wrote a sorting process for him in the middle, one y in 20 minutes. At this time, the start should be quite smooth, but the tragedy is now officially started. Then I continued to write d. tracyzhu said that there was a template for finding the intersection of line segments in the black book, so I typed out the functions one by one. I just typed several functions, tracyzhu and LJ said that they have figured out the f question DP. I really want to write my d, and then asked them if their ideas are mature. They firmly say OK. Then I reluctantly sent my computer out and read other questions. By the way, I thought about D. After more than 40 minutes, they finished writing, and the sample was wrong, and then they had to repair and make up for n times. I had to watch and do nothing to help them tune up, I hate that kind of detail, which is disgusting. I can calculate the subscripts. In the end, I went to check their program, and the three people had to struggle for a long time. In the last three hours, I called out the bug and handed it over. 1y, in fact, you only need to change one sentence at the very beginning. Unfortunately, three people had a bit of disorder at the time, so they couldn't wait to take a closer look at the program. After question F came out, I went all out to work on D. In fact, I already thought clearly. In the infinite distance of the ray, a point and the source point constitute a line segment, then, the line segment and the edges of all polygon determine whether the intersection point is located, record which polygon belongs to the intersection point, and then sort the distance from the intersection point to the source point from small to large, if the most recent focus belongs to the target polygon, the target is shot or not. 1 y in 20 minutes. The 1y of question D gave us a slight reply to the low morale, and then we found a big question. After a slight processing, we simulated it. Because of the writing problem, we could not deal with integers, it is very trivial to subtract an extremely small number from all numbers, remove the integer influence, and then pass it off, 3Y. At this time, there is only half an hour left, and it is basically impossible to have another one, so I began to eat leisurely --! At that time, when the Board was closed, five questions were listed in the last 25 rows. The tourism team had to be listed in the top 28 for silver. Although we had five questions, there were a huge number of fines, even if the four questions are no longer answered, we can barely rank 26, and the Silver Prize is almost hopeless. The last thing is true --! This RP ..

After that, I heard from WB that their question F has been violent. It is estimated that many teams have also made huge profits. It is no wonder that each team is a so fast --! Violence is a matter of several minutes. We have been struggling for more than two hours. It's depressing!