【LittleXi】ICPC2023 Nanjing Station Summary

【LittleXi】ICPC2023 Nanjing Station Summary

Before the game:

VP training twice a week

I played cf div2 normally, made up questions, settled down, and also vp’d twice (I’m addicted to the Internet)

Warm-up match

I got familiar with the keyboard and handed in the random algorithm for question A.

Tested and evaluated bitset, map, hashmap, and printing time (quite fast, took about 1 minute)

official match

Number of questions passed: 6

Rank: 65

Review:

• When I first came up, I looked at G first (because I felt the question was relatively simple), then looked at I at lhc, and looked at ABCD at zzy. Then lhc felt that I meant sign-in, so I wrote it directly, which was of course correct.
• Then I felt that the data range of G was a bit small, and then I thought about it in the direction of dp+greedy. It felt more right, so I communicated with zzy about the meaning of the question, played with the example, got hacked, and then modified it a little, like this If the example is right, it is right
• After I finished writing lhc and A dropped, I went up to write it. It took about 15 minutes to finish. Then a strange bug appeared. I kept correcting it and never corrected it. I asked zzy to read it together, and then I found out end() is written as begin(). It can only be said that it is determined by the factors of the competition venue and the reason why the keyboard and screen are not familiar (muscle memory will not make a mistake)
• Then zzy went to see C, and I went to see F. After a brief exchange with lhc, I felt that there was a very simple method, and it felt right!
• Then I spent 15 minutes writing it and passed the sample. Then I handed it in and passed it.
• After F passed, I went to see A. zzy and lhc continued to write C. A thought of a 1E9 approach and was thinking about how to optimize one dimension.
• I thought about the root divide and conquer algorithm, and it felt right (I didn’t realize the seriousness of the matter at this time). After logging in for 30 minutes, lhc and zzy passed C, and then I got on the computer and started writing (the beginning of sin) ), because this algorithm is still relatively difficult to write, so I wrote it for 1 hour, and then handed it in, and it was wa. I asked zzy to help me look at the code, and then it was hacked, and it was relatively fake, woo woo woo
• I got off the plane in shame, and then continued to think about A with zzy, lhc got on the machine and wrote L
• zzy came up with a conclusion (kangaroos in connected blocks are the same), and then I drew it twice to prove this conclusion. Then I thought about it for 5 minutes and came up with an O(nm) method, and it was right, so I wrote it on the computer. Got it
• I wrote it for about 30 minutes, and played it with my hands for 10 minutes. I passed it after I handed it in. Then I continued to write L in lhc. I thought about M and an algorithm. I wrote it for 20 minutes. Halfway through, I found that it was fake again qwq , lhc continues to write L and does not continue to occupy the machine time.
• I originally thought it was a stable silver, but in the last 20 minutes, M seemed to be unable to do it, so I went to see L. I thought of a similar greedy approach like them. In the last 3 minutes, I realized that I wanted to take mx, so I changed it and stared at the time. , in the last 45 seconds, handed it in, passed it in one shot, and completed the kill.

Postscript/Reflection:

• If you fail L, it will be Bronze 1, the most exciting episode.
• It’s a good way to make a bold guess, F will kill you immediately
• A and M are both fake. A doesn’t waste time. I guess I can touch the gold. Woo hoo, I’ll write it after thinking about it next time. It’s a bit stupid to catch the rain. I feel like I can do it.
• My teammates are very strong. I don’t think I can do it myself.