Preface
\ (\ text {10:00} \) finished the homework of the culture class happily, got the mother's consent and started playing the game!
The result \ (\ text {Rank37} \) is far worse than the previous one \ (34 \ cdots \ cdots \)
Ah, look at the title after opening title background found the topic of human brain hole a bit mean , look after the eggs came to understand everything ......
\ (\ text {T1} \ ) feeling a conclusion title, he did not write it ...... key decadent children will get for a while, then found autistic, and want to take \ (b \ equiv 0 \ pmod {25} \) of Partly divided.
Then it was seen as \ (b = 0 \) , when I was excited. . . \ (\ text {WA 0pt} \) , direct output of \ (0 \) is really a genius. .
Then autistic for a little while watching \ (\ text {T2} \) .
\ (\ text {T2} \) pushed the following formula and did not get the ideal result, and then found \ (n \ leq 5 \ times 10 ^ 4 \) . Huh? Huh? Isn't the Luogu evaluation machine very fast?
Then I gave up the violence of \ (O (n ^ 2) \) , \ (T \) made two points, \ (30pts \) . I hate the tumorsubtask
Uh huh, and then Ka Chang stuck. . And \ (T \) two points. At that time, I didn't notice \ (b_i \ leq 100 \) at all , and continued to work as usual.
The result was stuck a few times and didn't go in. Well, I put on the \ (O3 \) optimization template without hesitation , and then . . Then \ (\ text {AC} \) , there is a point \ (940ms \) to roll into the time limit. . .
(I gave this question a bad review later when I filled out the questionnaire)
After reading \ (\ text {T3} \), I felt that it was \ (\ text {dp} \) , but after writing \ (0.5h \), I found a bunch of details exploded, and it was useless for a long time. . Then a memory card, autistic own for a long time, called impossibleon the roll rough.
\ (\ text {T4} \) never learned probability and passed away.
\ (\ text {T5} \) The wire segment tree is divided into parts, but the sample explanations are too metaphysical, which makes it impossible to understand what the topic is saying. . . Then it exploded.
\ (\ text {T6} \) language question? Then the question is so long, just throw it away, go.
After scrolling back again, I found out that \ (\ text {T1} \) read the wrong question, and then picked up the \ (20 \) points. At that time, I thought that I wanted high precision and read it for myself \ (\ text {\ _ \ _ 128 } \) Still proud. .
In the end, \ (\ text {Rank37} \) is too weak.
to sum up
There is no second chance to submit a regular game, so read the questions carefully. The goal is to have the code fully open, and strive not to let the positive solutions come up with the details of the code.
postscript
After reading the solution, I found that the basic ideas I thought were all positive solutions, and then died in the details. . Especially the \ (\ text {dp} \) is the most pitted , I have written the equation and the transfer correctly , just when \ (80pts \) is about to get it, my answer is output f[n][k], there is no accumulation at all, and then goo , just I didn't think about the prefix and optimization at all.