CSP-S 2020 Travels

DAY 0

I hit the board in the morning before departure

The rest of the time is decadent

DAY 1

I was quite nervous before the exam, after all, this is the first major exam

There is no test machine for this year’s exam, and a virtual machine is used

At the beginning of the exam, I was not familiar with the virtual machine. When the virtual machine was turned on, there was an option to move or copy

I asked the invigilator. The invigilator said it was a problem with the machine, and then changed to another machine

After changing the machine, there is still such an option, and then I just choose one

The virtual machine is slow to boot, so go to the topic first

After reading the question of \(T1\), the virtual machine will boot

However, the window will not be enlarged after booting. It has been almost half an hour since the test started, so I can only continue typing in the small window

Because there was a lot of time wasted at the beginning, the idea of \(T1\) was not very clear at the beginning, basically it was thinking while playing.

So I didn’t notice that it was the Julian calendar before \(1582\), and the second example would not survive.

Then start outputting intermediate variable debugging

After discovering this problem, almost an hour later, I found that I had written all false

After the change, the second point of the second example is still unclear

Comparison of output intermediate variables and violence found that the loop section was found wrong

Quickly change the \(100\) cycle section to \(400\)

After the second example

But the third big example is still nothing

Basically in a state of always finding errors and correcting them, but still can’t get past the big sample

There is one and a half hours left in the exam, so I can only throw away \(T1\) first, and go see \(T2\)

\(T2\) seems to be much simpler than \(T1\), as long as you consider it according to the position, we have gone through the big example again

In the rest of the time, \(T3\) hit a violent line segment tree, and it can actually run through the large sample

\(T4\) played a very fake greedy, but couldn’t even survive the second example

It should be \(n=3\) or it can be passed

I adjusted \(T1\) in the last ten minutes and found that the boundary was judged wrong

Should be greater than to greater than or equal

After the change, the sample can be oversized

I checked the file name in the last ten minutes and the exam was over

DAY 2

When it was tested in Los Angeles, \(T1\) became \(40\)

Did not change the boundary of \(<2000\) to be greater than or equal to

In this way, when encountering \(1\) month \(1\) day, it will output \(13\) month \(1\) day

\(T2\) For everyone who forgot to mark \(vis\), the code loops from \(1\) to \(m\), which directly degenerates into violence \(65\) points

\(T3\) was stuck as \(30\) violent

\(T4\) ended up writing, and it ended up with \(5\) points

The total score is \(40+65+30+5=140\), it’s about to retire

DAY 10

\(CCF\) official data is out

Score \(60+80+70+0=210\)

Save \(rk17\), hovering on the edge of retirement

Reflection

\(1\). Be sure to read the questions first when you start the exam to get a general impression of the overall difficulty of the question

\(2\), don’t believe in big examples, be sure to make a few sets of extreme data

\(3\), don’t waste too much time on one question

\(4\), pay attention to observe the data range, whether you need to open \(long\ long\), \(unsigned\ long\ long\) or even high precision, one or two points can be judged specially