2022/3/10 exam summary

Time arrangement

7:30~7:40

Finish reading the questions , I don't seem to be able to ？

7:40~8:20

Find out T1 It's a network flow board , Write it quickly

8:20~8:40

Write a dfs Shoot violence

8:40~9:30

Suddenly found T2 It seems to be a string question
But still not very good , After thinking for a while, I found that I read the wrong question
And then , There is 60pts 了

9:30~9:50

Found that the array is replaced by map You can get through it T2 了

10:00~10:10

Washed a violent , But it is found that expectations cannot be rounded up , It's autistic

10:10~10:20

Think of a $K^3$ How to do it , It's estimated that if you don't score, you won't write

10:20~10:50

Analyzed why s Only 1e6, Then I naturally thought of different s Only $\log s$ individual
And then there is 50 Divide up
Then nothing happens

10:50~12：00

Right beat , Check

Summary of setting questions

T1

It's easy to think of this routine of turning a grid graph into a bipartite graph
But the implementation method , At first, I wrote the upper and lower bounds of the active sink
But not very good at writing , Just transform , Become an ordinary maximum flow
It's still difficult, but it's the opposite

T2

I almost missed the topic
But this problem is really simple
It can almost be regarded as a broad sense SAM The template questions

T3

In fact, it seems to have done a lot of this kind of rejection by dictating that some elements must be selected
But I only thought of rejecting the same dimension , I didn't think of how to get rid of something smaller than it
I didn't even think of it , In fact, the number of schemes smaller than it has been worked out , Just subtract it directly
Or do less of the problems of tolerance and exclusion , We must practice more