2022/5/18 exam summary

Time planning

7:00~7:50

T4 A see be sosdp/FWT, There will be some heavy places , Just excuse me , But it seems that direct tolerance and exclusion are not enough , But for 0/1/? Just accept and reject each other , It's easy to write , It will be finished soon , But got stuck 80pts

7:40~8:40

T2 The optimal order of is obviously to fill the number between the minimum and maximum , Sort , Enumerate minimum and maximum values , Maintain with overhead stack K Big , There is 40pts, But the answer may be negative , Initial value assignment 0 I've been looking for it for a long time

8:40~9:30

Section K It can be made of chairman tree , And then it came to mind IOI2014holiday, The practice of that question is monotony of decision
I made a list and found that there is really monotony in decision-making , So I began to write partition , It's easy to write , After writing for a while

9:30~10:00

T3 It seems to be a cost stream , Demolition point , then n^2 Run side by side ,, I don't know if I can run
The graph built at the beginning can only meet the maximum cost, but not the maximum flow , So it's OK to supplement the current and force the flow to be full
But it seems that only 80pts, Although it seems that the chairman tree can optimize the map , But there seemed to be many details, so I gave up

10:00~10:20

Want to T1, But after thinking for a while, there was no result , I can only write about violence

10:20~11:40

Think chain , Find that you can enumerate the maximum values and add points in turn , It seems that the dot divide and conquer can be extended to trees , So we began to divide and conquer , But it said that he gave up because of too many details , You can only write the points of the chain , After writing for a while

12:00~12:30

Find out T4 You can go to one L, Then change it and it will pass