7.24 simulation summary

The lunch was delicious ）

But I feel completely unable to eat staple food After eating, I began to feel uncomfortable in my stomach

My stomach is a little uncomfortable when I take a nap at noon Then sleep up and take the medicine and feel a little better

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In fact, if you don't knock T2 Go straight T3 It will be better Sobbing

Time arrangement

7.30-8.30

Look at the question See T1 This topological order reminds me of a mistake I made before （ But I can't remember the details I only remember it was a abc）

Then remember whether the network flow can do path coverage But I'm not impressed anymore

8.30-9.30

I thought about it for a while T1 I feel like I have no idea A violent fight

9.30-11.00

I thought about it for a while T2 How do you think it won't dp Not very able to make it up There is no way to fight with violence

11.00-12.30

blunt T3 Be aware of yourself T3 It can be divided into three grades

First gear violence Second gear Line tree bisection Third gear lct

11.00-11.20

The first file is written quickly But there's a problem diff All the time diff incorrect （ The state of mind has collapsed ） I can't write by hand check, check It's right to come out I ：？

11.20-11.30

So I repeated the above process several times Comforting yourself must be diff There is a problem

11.30-12.10

Speed of light write line segment tree dichotomy I wrote it on the binary card It's written by feeling

Then there is not enough time lct 了 Check check Just create a folder

Topic analysis

T1

violence For all inquiry points for Its side to see if it is in the query set

then dp dag The number of upper paths

T2

violence After enumeration check Is it legal

T3

1. violence find lca Then jump violently fa modify When asking dfs

2. Bisection on a line tree 1log maintain mx and mn To find the leftmost and rightmost position of a point

upd

The simpler way of writing is dichotomy + Line segment tree But one more log（ But it doesn't hurt

3. lct Maintain the information of real subtree and virtual subtree

upd

It was ordered after the game I wrote it for almost an hour and adjusted it for half an hour ） Maybe it will be faster to concentrate during the game ？ To say