GDKOI2021Day1 note

Overall: Why am I so embarrassed

T1

I chose the classic topic of the structure. It took 40 minutes to finish and the large sample was changed several times. It should be no problem.
Expectation: 100pts
Actual: 60pts
is 2~n-1 on both the abscissa and ordinate Range output reversed

T2

Seeing the title, I feel like I need to use the ST meter. I have no choice but to fight violence first, and then get an acceleration that can be close to the root level of violence. As a result, I slapped myself and it was nearly half of the time. Combine the violence and the optimized violence that hangs together, depending on the data scale
Expectation: 80pts
Actual: 80pts
standard

T3

Obviously greedy, but messed up (the fast queue is hit)...
Expectation: 5pts
actual: 20pts messed up
a miracle

T4

I didn’t expect a positive solution, but it’s not bad. It’s okay to run BFS with the minimum spanning tree.
~~Why didn’t I expect a positive solution.~~
Expectation: 50+pts (depending on the amount of water mixed in the data), estimated 55pts
Actual: 50pts
data is real

to sum up

Day1 still didn't play well, otherwise there is 340pts guaranteed. The main problem is that T3 and T4 are too complicated to think about, and I didn't expect a correct solution. T2 did not expect to use a monotonous queue. Come on tomorrow!
Expectation: 100+80+5+55=240pts
Actual: 60+80+20+50=210pts
is still planted